--- /dev/null
+/* Arrays.java -- Utility class with methods to operate on arrays
+ Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
+ Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING. If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library. Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module. An independent module is a module which is not derived from
+or based on this library. If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so. If you do not wish to do so, delete this
+exception statement from your version. */
+
+
+package java.util;
+
+import gnu.java.lang.CPStringBuilder;
+
+import java.io.Serializable;
+import java.lang.reflect.Array;
+
+/**
+ * This class contains various static utility methods performing operations on
+ * arrays, and a method to provide a List "view" of an array to facilitate
+ * using arrays with Collection-based APIs. All methods throw a
+ * {@link NullPointerException} if the parameter array is null.
+ * <p>
+ *
+ * Implementations may use their own algorithms, but must obey the general
+ * properties; for example, the sort must be stable and n*log(n) complexity.
+ * Sun's implementation of sort, and therefore ours, is a tuned quicksort,
+ * adapted from Jon L. Bentley and M. Douglas McIlroy's "Engineering a Sort
+ * Function", Software-Practice and Experience, Vol. 23(11) P. 1249-1265
+ * (November 1993). This algorithm offers n*log(n) performance on many data
+ * sets that cause other quicksorts to degrade to quadratic performance.
+ *
+ * @author Original author unknown
+ * @author Bryce McKinlay
+ * @author Eric Blake (ebb9@email.byu.edu)
+ * @see Comparable
+ * @see Comparator
+ * @since 1.2
+ * @status updated to 1.4
+ */
+public class Arrays
+{
+ /**
+ * This class is non-instantiable.
+ */
+ private Arrays()
+ {
+ }
+
+\f
+// binarySearch
+ /**
+ * Perform a binary search of a byte array for a key. The array must be
+ * sorted (as by the sort() method) - if it is not, the behaviour of this
+ * method is undefined, and may be an infinite loop. If the array contains
+ * the key more than once, any one of them may be found. Note: although the
+ * specification allows for an infinite loop if the array is unsorted, it
+ * will not happen in this implementation.
+ *
+ * @param a the array to search (must be sorted)
+ * @param key the value to search for
+ * @return the index at which the key was found, or -n-1 if it was not
+ * found, where n is the index of the first value higher than key or
+ * a.length if there is no such value.
+ */
+ public static int binarySearch(byte[] a, byte key)
+ {
+ if (a.length == 0)
+ return -1;
+ return binarySearch(a, 0, a.length - 1, key);
+ }
+
+ /**
+ * Perform a binary search of a range of a byte array for a key. The range
+ * must be sorted (as by the <code>sort(byte[], int, int)</code> method) -
+ * if it is not, the behaviour of this method is undefined, and may be an
+ * infinite loop. If the array contains the key more than once, any one of
+ * them may be found. Note: although the specification allows for an infinite
+ * loop if the array is unsorted, it will not happen in this implementation.
+ *
+ * @param a the array to search (must be sorted)
+ * @param low the lowest index to search from.
+ * @param hi the highest index to search to.
+ * @param key the value to search for
+ * @return the index at which the key was found, or -n-1 if it was not
+ * found, where n is the index of the first value higher than key or
+ * a.length if there is no such value.
+ * @throws IllegalArgumentException if <code>low > hi</code>
+ * @throws ArrayIndexOutOfBoundsException if <code>low < 0</code> or
+ * <code>hi > a.length</code>.
+ */
+ public static int binarySearch(byte[] a, int low, int hi, byte key)
+ {
+ if (low > hi)
+ throw new IllegalArgumentException("The start index is higher than " +
+ "the finish index.");
+ if (low < 0 || hi > a.length)
+ throw new ArrayIndexOutOfBoundsException("One of the indices is out " +
+ "of bounds.");
+ int mid = 0;
+ while (low <= hi)
+ {
+ mid = (low + hi) >>> 1;
+ final byte d = a[mid];
+ if (d == key)
+ return mid;
+ else if (d > key)
+ hi = mid - 1;
+ else
+ // This gets the insertion point right on the last loop.
+ low = ++mid;
+ }
+ return -mid - 1;
+ }
+
+ /**
+ * Perform a binary search of a char array for a key. The array must be
+ * sorted (as by the sort() method) - if it is not, the behaviour of this
+ * method is undefined, and may be an infinite loop. If the array contains
+ * the key more than once, any one of them may be found. Note: although the
+ * specification allows for an infinite loop if the array is unsorted, it
+ * will not happen in this implementation.
+ *
+ * @param a the array to search (must be sorted)
+ * @param key the value to search for
+ * @return the index at which the key was found, or -n-1 if it was not
+ * found, where n is the index of the first value higher than key or
+ * a.length if there is no such value.
+ */
+ public static int binarySearch(char[] a, char key)
+ {
+ if (a.length == 0)
+ return -1;
+ return binarySearch(a, 0, a.length - 1, key);
+ }
+
+ /**
+ * Perform a binary search of a range of a char array for a key. The range
+ * must be sorted (as by the <code>sort(char[], int, int)</code> method) -
+ * if it is not, the behaviour of this method is undefined, and may be an
+ * infinite loop. If the array contains the key more than once, any one of
+ * them may be found. Note: although the specification allows for an infinite
+ * loop if the array is unsorted, it will not happen in this implementation.
+ *
+ * @param a the array to search (must be sorted)
+ * @param low the lowest index to search from.
+ * @param hi the highest index to search to.
+ * @param key the value to search for
+ * @return the index at which the key was found, or -n-1 if it was not
+ * found, where n is the index of the first value higher than key or
+ * a.length if there is no such value.
+ * @throws IllegalArgumentException if <code>low > hi</code>
+ * @throws ArrayIndexOutOfBoundsException if <code>low < 0</code> or
+ * <code>hi > a.length</code>.
+ */
+ public static int binarySearch(char[] a, int low, int hi, char key)
+ {
+ if (low > hi)
+ throw new IllegalArgumentException("The start index is higher than " +
+ "the finish index.");
+ if (low < 0 || hi > a.length)
+ throw new ArrayIndexOutOfBoundsException("One of the indices is out " +
+ "of bounds.");
+ int mid = 0;
+ while (low <= hi)
+ {
+ mid = (low + hi) >>> 1;
+ final char d = a[mid];
+ if (d == key)
+ return mid;
+ else if (d > key)
+ hi = mid - 1;
+ else
+ // This gets the insertion point right on the last loop.
+ low = ++mid;
+ }
+ return -mid - 1;
+ }
+
+ /**
+ * Perform a binary search of a short array for a key. The array must be
+ * sorted (as by the sort() method) - if it is not, the behaviour of this
+ * method is undefined, and may be an infinite loop. If the array contains
+ * the key more than once, any one of them may be found. Note: although the
+ * specification allows for an infinite loop if the array is unsorted, it
+ * will not happen in this implementation.
+ *
+ * @param a the array to search (must be sorted)
+ * @param key the value to search for
+ * @return the index at which the key was found, or -n-1 if it was not
+ * found, where n is the index of the first value higher than key or
+ * a.length if there is no such value.
+ */
+ public static int binarySearch(short[] a, short key)
+ {
+ if (a.length == 0)
+ return -1;
+ return binarySearch(a, 0, a.length - 1, key);
+ }
+
+ /**
+ * Perform a binary search of a range of a short array for a key. The range
+ * must be sorted (as by the <code>sort(short[], int, int)</code> method) -
+ * if it is not, the behaviour of this method is undefined, and may be an
+ * infinite loop. If the array contains the key more than once, any one of
+ * them may be found. Note: although the specification allows for an infinite
+ * loop if the array is unsorted, it will not happen in this implementation.
+ *
+ * @param a the array to search (must be sorted)
+ * @param low the lowest index to search from.
+ * @param hi the highest index to search to.
+ * @param key the value to search for
+ * @return the index at which the key was found, or -n-1 if it was not
+ * found, where n is the index of the first value higher than key or
+ * a.length if there is no such value.
+ * @throws IllegalArgumentException if <code>low > hi</code>
+ * @throws ArrayIndexOutOfBoundsException if <code>low < 0</code> or
+ * <code>hi > a.length</code>.
+ */
+ public static int binarySearch(short[] a, int low, int hi, short key)
+ {
+ if (low > hi)
+ throw new IllegalArgumentException("The start index is higher than " +
+ "the finish index.");
+ if (low < 0 || hi > a.length)
+ throw new ArrayIndexOutOfBoundsException("One of the indices is out " +
+ "of bounds.");
+ int mid = 0;
+ while (low <= hi)
+ {
+ mid = (low + hi) >>> 1;
+ final short d = a[mid];
+ if (d == key)
+ return mid;
+ else if (d > key)
+ hi = mid - 1;
+ else
+ // This gets the insertion point right on the last loop.
+ low = ++mid;
+ }
+ return -mid - 1;
+ }
+
+ /**
+ * Perform a binary search of an int array for a key. The array must be
+ * sorted (as by the sort() method) - if it is not, the behaviour of this
+ * method is undefined, and may be an infinite loop. If the array contains
+ * the key more than once, any one of them may be found. Note: although the
+ * specification allows for an infinite loop if the array is unsorted, it
+ * will not happen in this implementation.
+ *
+ * @param a the array to search (must be sorted)
+ * @param key the value to search for
+ * @return the index at which the key was found, or -n-1 if it was not
+ * found, where n is the index of the first value higher than key or
+ * a.length if there is no such value.
+ */
+ public static int binarySearch(int[] a, int key)
+ {
+ if (a.length == 0)
+ return -1;
+ return binarySearch(a, 0, a.length - 1, key);
+ }
+
+ /**
+ * Perform a binary search of a range of an integer array for a key. The range
+ * must be sorted (as by the <code>sort(int[], int, int)</code> method) -
+ * if it is not, the behaviour of this method is undefined, and may be an
+ * infinite loop. If the array contains the key more than once, any one of
+ * them may be found. Note: although the specification allows for an infinite
+ * loop if the array is unsorted, it will not happen in this implementation.
+ *
+ * @param a the array to search (must be sorted)
+ * @param low the lowest index to search from.
+ * @param hi the highest index to search to.
+ * @param key the value to search for
+ * @return the index at which the key was found, or -n-1 if it was not
+ * found, where n is the index of the first value higher than key or
+ * a.length if there is no such value.
+ * @throws IllegalArgumentException if <code>low > hi</code>
+ * @throws ArrayIndexOutOfBoundsException if <code>low < 0</code> or
+ * <code>hi > a.length</code>.
+ */
+ public static int binarySearch(int[] a, int low, int hi, int key)
+ {
+ if (low > hi)
+ throw new IllegalArgumentException("The start index is higher than " +
+ "the finish index.");
+ if (low < 0 || hi > a.length)
+ throw new ArrayIndexOutOfBoundsException("One of the indices is out " +
+ "of bounds.");
+ int mid = 0;
+ while (low <= hi)
+ {
+ mid = (low + hi) >>> 1;
+ final int d = a[mid];
+ if (d == key)
+ return mid;
+ else if (d > key)
+ hi = mid - 1;
+ else
+ // This gets the insertion point right on the last loop.
+ low = ++mid;
+ }
+ return -mid - 1;
+ }
+
+ /**
+ * Perform a binary search of a long array for a key. The array must be
+ * sorted (as by the sort() method) - if it is not, the behaviour of this
+ * method is undefined, and may be an infinite loop. If the array contains
+ * the key more than once, any one of them may be found. Note: although the
+ * specification allows for an infinite loop if the array is unsorted, it
+ * will not happen in this implementation.
+ *
+ * @param a the array to search (must be sorted)
+ * @param key the value to search for
+ * @return the index at which the key was found, or -n-1 if it was not
+ * found, where n is the index of the first value higher than key or
+ * a.length if there is no such value.
+ */
+ public static int binarySearch(long[] a, long key)
+ {
+ if (a.length == 0)
+ return -1;
+ return binarySearch(a, 0, a.length - 1, key);
+ }
+
+ /**
+ * Perform a binary search of a range of a long array for a key. The range
+ * must be sorted (as by the <code>sort(long[], int, int)</code> method) -
+ * if it is not, the behaviour of this method is undefined, and may be an
+ * infinite loop. If the array contains the key more than once, any one of
+ * them may be found. Note: although the specification allows for an infinite
+ * loop if the array is unsorted, it will not happen in this implementation.
+ *
+ * @param a the array to search (must be sorted)
+ * @param low the lowest index to search from.
+ * @param hi the highest index to search to.
+ * @param key the value to search for
+ * @return the index at which the key was found, or -n-1 if it was not
+ * found, where n is the index of the first value higher than key or
+ * a.length if there is no such value.
+ * @throws IllegalArgumentException if <code>low > hi</code>
+ * @throws ArrayIndexOutOfBoundsException if <code>low < 0</code> or
+ * <code>hi > a.length</code>.
+ */
+ public static int binarySearch(long[] a, int low, int hi, long key)
+ {
+ if (low > hi)
+ throw new IllegalArgumentException("The start index is higher than " +
+ "the finish index.");
+ if (low < 0 || hi > a.length)
+ throw new ArrayIndexOutOfBoundsException("One of the indices is out " +
+ "of bounds.");
+ int mid = 0;
+ while (low <= hi)
+ {
+ mid = (low + hi) >>> 1;
+ final long d = a[mid];
+ if (d == key)
+ return mid;
+ else if (d > key)
+ hi = mid - 1;
+ else
+ // This gets the insertion point right on the last loop.
+ low = ++mid;
+ }
+ return -mid - 1;
+ }
+
+ /**
+ * Perform a binary search of a float array for a key. The array must be
+ * sorted (as by the sort() method) - if it is not, the behaviour of this
+ * method is undefined, and may be an infinite loop. If the array contains
+ * the key more than once, any one of them may be found. Note: although the
+ * specification allows for an infinite loop if the array is unsorted, it
+ * will not happen in this implementation.
+ *
+ * @param a the array to search (must be sorted)
+ * @param key the value to search for
+ * @return the index at which the key was found, or -n-1 if it was not
+ * found, where n is the index of the first value higher than key or
+ * a.length if there is no such value.
+ */
+ public static int binarySearch(float[] a, float key)
+ {
+ if (a.length == 0)
+ return -1;
+ return binarySearch(a, 0, a.length - 1, key);
+ }
+
+ /**
+ * Perform a binary search of a range of a float array for a key. The range
+ * must be sorted (as by the <code>sort(float[], int, int)</code> method) -
+ * if it is not, the behaviour of this method is undefined, and may be an
+ * infinite loop. If the array contains the key more than once, any one of
+ * them may be found. Note: although the specification allows for an infinite
+ * loop if the array is unsorted, it will not happen in this implementation.
+ *
+ * @param a the array to search (must be sorted)
+ * @param low the lowest index to search from.
+ * @param hi the highest index to search to.
+ * @param key the value to search for
+ * @return the index at which the key was found, or -n-1 if it was not
+ * found, where n is the index of the first value higher than key or
+ * a.length if there is no such value.
+ * @throws IllegalArgumentException if <code>low > hi</code>
+ * @throws ArrayIndexOutOfBoundsException if <code>low < 0</code> or
+ * <code>hi > a.length</code>.
+ */
+ public static int binarySearch(float[] a, int low, int hi, float key)
+ {
+ if (low > hi)
+ throw new IllegalArgumentException("The start index is higher than " +
+ "the finish index.");
+ if (low < 0 || hi > a.length)
+ throw new ArrayIndexOutOfBoundsException("One of the indices is out " +
+ "of bounds.");
+ // Must use Float.compare to take into account NaN, +-0.
+ int mid = 0;
+ while (low <= hi)
+ {
+ mid = (low + hi) >>> 1;
+ final int r = Float.compare(a[mid], key);
+ if (r == 0)
+ return mid;
+ else if (r > 0)
+ hi = mid - 1;
+ else
+ // This gets the insertion point right on the last loop
+ low = ++mid;
+ }
+ return -mid - 1;
+ }
+
+ /**
+ * Perform a binary search of a double array for a key. The array must be
+ * sorted (as by the sort() method) - if it is not, the behaviour of this
+ * method is undefined, and may be an infinite loop. If the array contains
+ * the key more than once, any one of them may be found. Note: although the
+ * specification allows for an infinite loop if the array is unsorted, it
+ * will not happen in this implementation.
+ *
+ * @param a the array to search (must be sorted)
+ * @param key the value to search for
+ * @return the index at which the key was found, or -n-1 if it was not
+ * found, where n is the index of the first value higher than key or
+ * a.length if there is no such value.
+ */
+ public static int binarySearch(double[] a, double key)
+ {
+ if (a.length == 0)
+ return -1;
+ return binarySearch(a, 0, a.length - 1, key);
+ }
+
+ /**
+ * Perform a binary search of a range of a double array for a key. The range
+ * must be sorted (as by the <code>sort(double[], int, int)</code> method) -
+ * if it is not, the behaviour of this method is undefined, and may be an
+ * infinite loop. If the array contains the key more than once, any one of
+ * them may be found. Note: although the specification allows for an infinite
+ * loop if the array is unsorted, it will not happen in this implementation.
+ *
+ * @param a the array to search (must be sorted)
+ * @param low the lowest index to search from.
+ * @param hi the highest index to search to.
+ * @param key the value to search for
+ * @return the index at which the key was found, or -n-1 if it was not
+ * found, where n is the index of the first value higher than key or
+ * a.length if there is no such value.
+ * @throws IllegalArgumentException if <code>low > hi</code>
+ * @throws ArrayIndexOutOfBoundsException if <code>low < 0</code> or
+ * <code>hi > a.length</code>.
+ */
+ public static int binarySearch(double[] a, int low, int hi, double key)
+ {
+ if (low > hi)
+ throw new IllegalArgumentException("The start index is higher than " +
+ "the finish index.");
+ if (low < 0 || hi > a.length)
+ throw new ArrayIndexOutOfBoundsException("One of the indices is out " +
+ "of bounds.");
+ // Must use Double.compare to take into account NaN, +-0.
+ int mid = 0;
+ while (low <= hi)
+ {
+ mid = (low + hi) >>> 1;
+ final int r = Double.compare(a[mid], key);
+ if (r == 0)
+ return mid;
+ else if (r > 0)
+ hi = mid - 1;
+ else
+ // This gets the insertion point right on the last loop
+ low = ++mid;
+ }
+ return -mid - 1;
+ }
+
+ /**
+ * Perform a binary search of an Object array for a key, using the natural
+ * ordering of the elements. The array must be sorted (as by the sort()
+ * method) - if it is not, the behaviour of this method is undefined, and may
+ * be an infinite loop. Further, the key must be comparable with every item
+ * in the array. If the array contains the key more than once, any one of
+ * them may be found. Note: although the specification allows for an infinite
+ * loop if the array is unsorted, it will not happen in this (JCL)
+ * implementation.
+ *
+ * @param a the array to search (must be sorted)
+ * @param key the value to search for
+ * @return the index at which the key was found, or -n-1 if it was not
+ * found, where n is the index of the first value higher than key or
+ * a.length if there is no such value.
+ * @throws ClassCastException if key could not be compared with one of the
+ * elements of a
+ * @throws NullPointerException if a null element in a is compared
+ */
+ public static int binarySearch(Object[] a, Object key)
+ {
+ if (a.length == 0)
+ return -1;
+ return binarySearch(a, key, null);
+ }
+
+ /**
+ * Perform a binary search of a range of an Object array for a key. The range
+ * must be sorted (as by the <code>sort(Object[], int, int)</code> method) -
+ * if it is not, the behaviour of this method is undefined, and may be an
+ * infinite loop. If the array contains the key more than once, any one of
+ * them may be found. Note: although the specification allows for an infinite
+ * loop if the array is unsorted, it will not happen in this implementation.
+ *
+ * @param a the array to search (must be sorted)
+ * @param low the lowest index to search from.
+ * @param hi the highest index to search to.
+ * @param key the value to search for
+ * @return the index at which the key was found, or -n-1 if it was not
+ * found, where n is the index of the first value higher than key or
+ * a.length if there is no such value.
+ */
+ public static int binarySearch(Object[] a, int low, int hi, Object key)
+ {
+ return binarySearch(a, low, hi, key, null);
+ }
+
+ /**
+ * Perform a binary search of an Object array for a key, using a supplied
+ * Comparator. The array must be sorted (as by the sort() method with the
+ * same Comparator) - if it is not, the behaviour of this method is
+ * undefined, and may be an infinite loop. Further, the key must be
+ * comparable with every item in the array. If the array contains the key
+ * more than once, any one of them may be found. Note: although the
+ * specification allows for an infinite loop if the array is unsorted, it
+ * will not happen in this (JCL) implementation.
+ *
+ * @param a the array to search (must be sorted)
+ * @param key the value to search for
+ * @param c the comparator by which the array is sorted; or null to
+ * use the elements' natural order
+ * @return the index at which the key was found, or -n-1 if it was not
+ * found, where n is the index of the first value higher than key or
+ * a.length if there is no such value.
+ * @throws ClassCastException if key could not be compared with one of the
+ * elements of a
+ * @throws NullPointerException if a null element is compared with natural
+ * ordering (only possible when c is null)
+ */
+ public static <T> int binarySearch(T[] a, T key, Comparator<? super T> c)
+ {
+ if (a.length == 0)
+ return -1;
+ return binarySearch(a, 0, a.length - 1, key, c);
+ }
+
+ /**
+ * Perform a binary search of a range of an Object array for a key using
+ * a {@link Comparator}. The range must be sorted (as by the
+ * <code>sort(Object[], int, int)</code> method) - if it is not, the
+ * behaviour of this method is undefined, and may be an infinite loop. If
+ * the array contains the key more than once, any one of them may be found.
+ * Note: although the specification allows for an infinite loop if the array
+ * is unsorted, it will not happen in this implementation.
+ *
+ * @param a the array to search (must be sorted)
+ * @param low the lowest index to search from.
+ * @param hi the highest index to search to.
+ * @param key the value to search for
+ * @param c the comparator by which the array is sorted; or null to
+ * use the elements' natural order
+ * @return the index at which the key was found, or -n-1 if it was not
+ * found, where n is the index of the first value higher than key or
+ * a.length if there is no such value.
+ * @throws ClassCastException if key could not be compared with one of the
+ * elements of a
+ * @throws IllegalArgumentException if <code>low > hi</code>
+ * @throws ArrayIndexOutOfBoundsException if <code>low < 0</code> or
+ * <code>hi > a.length</code>.
+ */
+ public static <T> int binarySearch(T[] a, int low, int hi, T key,
+ Comparator<? super T> c)
+ {
+ if (low > hi)
+ throw new IllegalArgumentException("The start index is higher than " +
+ "the finish index.");
+ if (low < 0 || hi > a.length)
+ throw new ArrayIndexOutOfBoundsException("One of the indices is out " +
+ "of bounds.");
+ int mid = 0;
+ while (low <= hi)
+ {
+ mid = (low + hi) >>> 1;
+ // NOTE: Please keep the order of a[mid] and key. Although
+ // not required by the specs, the RI has it in this order as
+ // well, and real programs (erroneously) depend on it.
+ final int d = Collections.compare(a[mid], key, c);
+ if (d == 0)
+ return mid;
+ else if (d > 0)
+ hi = mid - 1;
+ else
+ // This gets the insertion point right on the last loop
+ low = ++mid;
+ }
+ return -mid - 1;
+ }
+
+\f
+// equals
+ /**
+ * Compare two boolean arrays for equality.
+ *
+ * @param a1 the first array to compare
+ * @param a2 the second array to compare
+ * @return true if a1 and a2 are both null, or if a2 is of the same length
+ * as a1, and for each 0 <= i < a1.length, a1[i] == a2[i]
+ */
+ public static boolean equals(boolean[] a1, boolean[] a2)
+ {
+ // Quick test which saves comparing elements of the same array, and also
+ // catches the case that both are null.
+ if (a1 == a2)
+ return true;
+
+ if (null == a1 || null == a2)
+ return false;
+
+ // If they're the same length, test each element
+ if (a1.length == a2.length)
+ {
+ int i = a1.length;
+ while (--i >= 0)
+ if (a1[i] != a2[i])
+ return false;
+ return true;
+ }
+ return false;
+ }
+
+ /**
+ * Compare two byte arrays for equality.
+ *
+ * @param a1 the first array to compare
+ * @param a2 the second array to compare
+ * @return true if a1 and a2 are both null, or if a2 is of the same length
+ * as a1, and for each 0 <= i < a1.length, a1[i] == a2[i]
+ */
+ public static boolean equals(byte[] a1, byte[] a2)
+ {
+ // Quick test which saves comparing elements of the same array, and also
+ // catches the case that both are null.
+ if (a1 == a2)
+ return true;
+
+ if (null == a1 || null == a2)
+ return false;
+
+ // If they're the same length, test each element
+ if (a1.length == a2.length)
+ {
+ int i = a1.length;
+ while (--i >= 0)
+ if (a1[i] != a2[i])
+ return false;
+ return true;
+ }
+ return false;
+ }
+
+ /**
+ * Compare two char arrays for equality.
+ *
+ * @param a1 the first array to compare
+ * @param a2 the second array to compare
+ * @return true if a1 and a2 are both null, or if a2 is of the same length
+ * as a1, and for each 0 <= i < a1.length, a1[i] == a2[i]
+ */
+ public static boolean equals(char[] a1, char[] a2)
+ {
+ // Quick test which saves comparing elements of the same array, and also
+ // catches the case that both are null.
+ if (a1 == a2)
+ return true;
+
+ if (null == a1 || null == a2)
+ return false;
+
+ // If they're the same length, test each element
+ if (a1.length == a2.length)
+ {
+ int i = a1.length;
+ while (--i >= 0)
+ if (a1[i] != a2[i])
+ return false;
+ return true;
+ }
+ return false;
+ }
+
+ /**
+ * Compare two short arrays for equality.
+ *
+ * @param a1 the first array to compare
+ * @param a2 the second array to compare
+ * @return true if a1 and a2 are both null, or if a2 is of the same length
+ * as a1, and for each 0 <= i < a1.length, a1[i] == a2[i]
+ */
+ public static boolean equals(short[] a1, short[] a2)
+ {
+ // Quick test which saves comparing elements of the same array, and also
+ // catches the case that both are null.
+ if (a1 == a2)
+ return true;
+
+ if (null == a1 || null == a2)
+ return false;
+
+ // If they're the same length, test each element
+ if (a1.length == a2.length)
+ {
+ int i = a1.length;
+ while (--i >= 0)
+ if (a1[i] != a2[i])
+ return false;
+ return true;
+ }
+ return false;
+ }
+
+ /**
+ * Compare two int arrays for equality.
+ *
+ * @param a1 the first array to compare
+ * @param a2 the second array to compare
+ * @return true if a1 and a2 are both null, or if a2 is of the same length
+ * as a1, and for each 0 <= i < a1.length, a1[i] == a2[i]
+ */
+ public static boolean equals(int[] a1, int[] a2)
+ {
+ // Quick test which saves comparing elements of the same array, and also
+ // catches the case that both are null.
+ if (a1 == a2)
+ return true;
+
+ if (null == a1 || null == a2)
+ return false;
+
+ // If they're the same length, test each element
+ if (a1.length == a2.length)
+ {
+ int i = a1.length;
+ while (--i >= 0)
+ if (a1[i] != a2[i])
+ return false;
+ return true;
+ }
+ return false;
+ }
+
+ /**
+ * Compare two long arrays for equality.
+ *
+ * @param a1 the first array to compare
+ * @param a2 the second array to compare
+ * @return true if a1 and a2 are both null, or if a2 is of the same length
+ * as a1, and for each 0 <= i < a1.length, a1[i] == a2[i]
+ */
+ public static boolean equals(long[] a1, long[] a2)
+ {
+ // Quick test which saves comparing elements of the same array, and also
+ // catches the case that both are null.
+ if (a1 == a2)
+ return true;
+
+ if (null == a1 || null == a2)
+ return false;
+
+ // If they're the same length, test each element
+ if (a1.length == a2.length)
+ {
+ int i = a1.length;
+ while (--i >= 0)
+ if (a1[i] != a2[i])
+ return false;
+ return true;
+ }
+ return false;
+ }
+
+ /**
+ * Compare two float arrays for equality.
+ *
+ * @param a1 the first array to compare
+ * @param a2 the second array to compare
+ * @return true if a1 and a2 are both null, or if a2 is of the same length
+ * as a1, and for each 0 <= i < a1.length, a1[i] == a2[i]
+ */
+ public static boolean equals(float[] a1, float[] a2)
+ {
+ // Quick test which saves comparing elements of the same array, and also
+ // catches the case that both are null.
+ if (a1 == a2)
+ return true;
+
+ if (null == a1 || null == a2)
+ return false;
+
+ // Must use Float.compare to take into account NaN, +-0.
+ // If they're the same length, test each element
+ if (a1.length == a2.length)
+ {
+ int i = a1.length;
+ while (--i >= 0)
+ if (Float.compare(a1[i], a2[i]) != 0)
+ return false;
+ return true;
+ }
+ return false;
+ }
+
+ /**
+ * Compare two double arrays for equality.
+ *
+ * @param a1 the first array to compare
+ * @param a2 the second array to compare
+ * @return true if a1 and a2 are both null, or if a2 is of the same length
+ * as a1, and for each 0 <= i < a1.length, a1[i] == a2[i]
+ */
+ public static boolean equals(double[] a1, double[] a2)
+ {
+ // Quick test which saves comparing elements of the same array, and also
+ // catches the case that both are null.
+ if (a1 == a2)
+ return true;
+
+ if (null == a1 || null == a2)
+ return false;
+
+ // Must use Double.compare to take into account NaN, +-0.
+ // If they're the same length, test each element
+ if (a1.length == a2.length)
+ {
+ int i = a1.length;
+ while (--i >= 0)
+ if (Double.compare(a1[i], a2[i]) != 0)
+ return false;
+ return true;
+ }
+ return false;
+ }
+
+ /**
+ * Compare two Object arrays for equality.
+ *
+ * @param a1 the first array to compare
+ * @param a2 the second array to compare
+ * @return true if a1 and a2 are both null, or if a1 is of the same length
+ * as a2, and for each 0 <= i < a.length, a1[i] == null ?
+ * a2[i] == null : a1[i].equals(a2[i]).
+ */
+ public static boolean equals(Object[] a1, Object[] a2)
+ {
+ // Quick test which saves comparing elements of the same array, and also
+ // catches the case that both are null.
+ if (a1 == a2)
+ return true;
+
+ if (null == a1 || null == a2)
+ return false;
+
+ // If they're the same length, test each element
+ if (a1.length == a2.length)
+ {
+ int i = a1.length;
+ while (--i >= 0)
+ if (! AbstractCollection.equals(a1[i], a2[i]))
+ return false;
+ return true;
+ }
+ return false;
+ }
+
+\f
+// fill
+ /**
+ * Fill an array with a boolean value.
+ *
+ * @param a the array to fill
+ * @param val the value to fill it with
+ */
+ public static void fill(boolean[] a, boolean val)
+ {
+ fill(a, 0, a.length, val);
+ }
+
+ /**
+ * Fill a range of an array with a boolean value.
+ *
+ * @param a the array to fill
+ * @param fromIndex the index to fill from, inclusive
+ * @param toIndex the index to fill to, exclusive
+ * @param val the value to fill with
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0
+ * || toIndex > a.length
+ */
+ public static void fill(boolean[] a, int fromIndex, int toIndex, boolean val)
+ {
+ if (fromIndex > toIndex)
+ throw new IllegalArgumentException();
+ for (int i = fromIndex; i < toIndex; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Fill an array with a byte value.
+ *
+ * @param a the array to fill
+ * @param val the value to fill it with
+ */
+ public static void fill(byte[] a, byte val)
+ {
+ fill(a, 0, a.length, val);
+ }
+
+ /**
+ * Fill a range of an array with a byte value.
+ *
+ * @param a the array to fill
+ * @param fromIndex the index to fill from, inclusive
+ * @param toIndex the index to fill to, exclusive
+ * @param val the value to fill with
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0
+ * || toIndex > a.length
+ */
+ public static void fill(byte[] a, int fromIndex, int toIndex, byte val)
+ {
+ if (fromIndex > toIndex)
+ throw new IllegalArgumentException();
+ for (int i = fromIndex; i < toIndex; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Fill an array with a char value.
+ *
+ * @param a the array to fill
+ * @param val the value to fill it with
+ */
+ public static void fill(char[] a, char val)
+ {
+ fill(a, 0, a.length, val);
+ }
+
+ /**
+ * Fill a range of an array with a char value.
+ *
+ * @param a the array to fill
+ * @param fromIndex the index to fill from, inclusive
+ * @param toIndex the index to fill to, exclusive
+ * @param val the value to fill with
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0
+ * || toIndex > a.length
+ */
+ public static void fill(char[] a, int fromIndex, int toIndex, char val)
+ {
+ if (fromIndex > toIndex)
+ throw new IllegalArgumentException();
+ for (int i = fromIndex; i < toIndex; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Fill an array with a short value.
+ *
+ * @param a the array to fill
+ * @param val the value to fill it with
+ */
+ public static void fill(short[] a, short val)
+ {
+ fill(a, 0, a.length, val);
+ }
+
+ /**
+ * Fill a range of an array with a short value.
+ *
+ * @param a the array to fill
+ * @param fromIndex the index to fill from, inclusive
+ * @param toIndex the index to fill to, exclusive
+ * @param val the value to fill with
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0
+ * || toIndex > a.length
+ */
+ public static void fill(short[] a, int fromIndex, int toIndex, short val)
+ {
+ if (fromIndex > toIndex)
+ throw new IllegalArgumentException();
+ for (int i = fromIndex; i < toIndex; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Fill an array with an int value.
+ *
+ * @param a the array to fill
+ * @param val the value to fill it with
+ */
+ public static void fill(int[] a, int val)
+ {
+ fill(a, 0, a.length, val);
+ }
+
+ /**
+ * Fill a range of an array with an int value.
+ *
+ * @param a the array to fill
+ * @param fromIndex the index to fill from, inclusive
+ * @param toIndex the index to fill to, exclusive
+ * @param val the value to fill with
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0
+ * || toIndex > a.length
+ */
+ public static void fill(int[] a, int fromIndex, int toIndex, int val)
+ {
+ if (fromIndex > toIndex)
+ throw new IllegalArgumentException();
+ for (int i = fromIndex; i < toIndex; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Fill an array with a long value.
+ *
+ * @param a the array to fill
+ * @param val the value to fill it with
+ */
+ public static void fill(long[] a, long val)
+ {
+ fill(a, 0, a.length, val);
+ }
+
+ /**
+ * Fill a range of an array with a long value.
+ *
+ * @param a the array to fill
+ * @param fromIndex the index to fill from, inclusive
+ * @param toIndex the index to fill to, exclusive
+ * @param val the value to fill with
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0
+ * || toIndex > a.length
+ */
+ public static void fill(long[] a, int fromIndex, int toIndex, long val)
+ {
+ if (fromIndex > toIndex)
+ throw new IllegalArgumentException();
+ for (int i = fromIndex; i < toIndex; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Fill an array with a float value.
+ *
+ * @param a the array to fill
+ * @param val the value to fill it with
+ */
+ public static void fill(float[] a, float val)
+ {
+ fill(a, 0, a.length, val);
+ }
+
+ /**
+ * Fill a range of an array with a float value.
+ *
+ * @param a the array to fill
+ * @param fromIndex the index to fill from, inclusive
+ * @param toIndex the index to fill to, exclusive
+ * @param val the value to fill with
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0
+ * || toIndex > a.length
+ */
+ public static void fill(float[] a, int fromIndex, int toIndex, float val)
+ {
+ if (fromIndex > toIndex)
+ throw new IllegalArgumentException();
+ for (int i = fromIndex; i < toIndex; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Fill an array with a double value.
+ *
+ * @param a the array to fill
+ * @param val the value to fill it with
+ */
+ public static void fill(double[] a, double val)
+ {
+ fill(a, 0, a.length, val);
+ }
+
+ /**
+ * Fill a range of an array with a double value.
+ *
+ * @param a the array to fill
+ * @param fromIndex the index to fill from, inclusive
+ * @param toIndex the index to fill to, exclusive
+ * @param val the value to fill with
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0
+ * || toIndex > a.length
+ */
+ public static void fill(double[] a, int fromIndex, int toIndex, double val)
+ {
+ if (fromIndex > toIndex)
+ throw new IllegalArgumentException();
+ for (int i = fromIndex; i < toIndex; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Fill an array with an Object value.
+ *
+ * @param a the array to fill
+ * @param val the value to fill it with
+ * @throws ClassCastException if val is not an instance of the element
+ * type of a.
+ */
+ public static void fill(Object[] a, Object val)
+ {
+ fill(a, 0, a.length, val);
+ }
+
+ /**
+ * Fill a range of an array with an Object value.
+ *
+ * @param a the array to fill
+ * @param fromIndex the index to fill from, inclusive
+ * @param toIndex the index to fill to, exclusive
+ * @param val the value to fill with
+ * @throws ClassCastException if val is not an instance of the element
+ * type of a.
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0
+ * || toIndex > a.length
+ */
+ public static void fill(Object[] a, int fromIndex, int toIndex, Object val)
+ {
+ if (fromIndex > toIndex)
+ throw new IllegalArgumentException();
+ for (int i = fromIndex; i < toIndex; i++)
+ a[i] = val;
+ }
+
+\f
+// sort
+ // Thanks to Paul Fisher (rao@gnu.org) for finding this quicksort algorithm
+ // as specified by Sun and porting it to Java. The algorithm is an optimised
+ // quicksort, as described in Jon L. Bentley and M. Douglas McIlroy's
+ // "Engineering a Sort Function", Software-Practice and Experience, Vol.
+ // 23(11) P. 1249-1265 (November 1993). This algorithm gives n*log(n)
+ // performance on many arrays that would take quadratic time with a standard
+ // quicksort.
+
+ /**
+ * Performs a stable sort on the elements, arranging them according to their
+ * natural order.
+ *
+ * @param a the byte array to sort
+ */
+ public static void sort(byte[] a)
+ {
+ qsort(a, 0, a.length);
+ }
+
+ /**
+ * Performs a stable sort on the elements, arranging them according to their
+ * natural order.
+ *
+ * @param a the byte array to sort
+ * @param fromIndex the first index to sort (inclusive)
+ * @param toIndex the last index to sort (exclusive)
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0
+ * || toIndex > a.length
+ */
+ public static void sort(byte[] a, int fromIndex, int toIndex)
+ {
+ if (fromIndex > toIndex)
+ throw new IllegalArgumentException();
+ if (fromIndex < 0)
+ throw new ArrayIndexOutOfBoundsException();
+ qsort(a, fromIndex, toIndex - fromIndex);
+ }
+
+ /**
+ * Finds the index of the median of three array elements.
+ *
+ * @param a the first index
+ * @param b the second index
+ * @param c the third index
+ * @param d the array
+ * @return the index (a, b, or c) which has the middle value of the three
+ */
+ private static int med3(int a, int b, int c, byte[] d)
+ {
+ return (d[a] < d[b]
+ ? (d[b] < d[c] ? b : d[a] < d[c] ? c : a)
+ : (d[b] > d[c] ? b : d[a] > d[c] ? c : a));
+ }
+
+ /**
+ * Swaps the elements at two locations of an array
+ *
+ * @param i the first index
+ * @param j the second index
+ * @param a the array
+ */
+ private static void swap(int i, int j, byte[] a)
+ {
+ byte c = a[i];
+ a[i] = a[j];
+ a[j] = c;
+ }
+
+ /**
+ * Swaps two ranges of an array.
+ *
+ * @param i the first range start
+ * @param j the second range start
+ * @param n the element count
+ * @param a the array
+ */
+ private static void vecswap(int i, int j, int n, byte[] a)
+ {
+ for ( ; n > 0; i++, j++, n--)
+ swap(i, j, a);
+ }
+
+ /**
+ * Performs a recursive modified quicksort.
+ *
+ * @param array the array to sort
+ * @param from the start index (inclusive)
+ * @param count the number of elements to sort
+ */
+ private static void qsort(byte[] array, int from, int count)
+ {
+ // Use an insertion sort on small arrays.
+ if (count <= 7)
+ {
+ for (int i = from + 1; i < from + count; i++)
+ for (int j = i; j > from && array[j - 1] > array[j]; j--)
+ swap(j, j - 1, array);
+ return;
+ }
+
+ // Determine a good median element.
+ int mid = from + count / 2;
+ int lo = from;
+ int hi = from + count - 1;
+
+ if (count > 40)
+ { // big arrays, pseudomedian of 9
+ int s = count / 8;
+ lo = med3(lo, lo + s, lo + 2 * s, array);
+ mid = med3(mid - s, mid, mid + s, array);
+ hi = med3(hi - 2 * s, hi - s, hi, array);
+ }
+ mid = med3(lo, mid, hi, array);
+
+ int a, b, c, d;
+ int comp;
+
+ // Pull the median element out of the fray, and use it as a pivot.
+ swap(from, mid, array);
+ a = b = from;
+ c = d = from + count - 1;
+
+ // Repeatedly move b and c to each other, swapping elements so
+ // that all elements before index b are less than the pivot, and all
+ // elements after index c are greater than the pivot. a and b track
+ // the elements equal to the pivot.
+ while (true)
+ {
+ while (b <= c && (comp = array[b] - array[from]) <= 0)
+ {
+ if (comp == 0)
+ {
+ swap(a, b, array);
+ a++;
+ }
+ b++;
+ }
+ while (c >= b && (comp = array[c] - array[from]) >= 0)
+ {
+ if (comp == 0)
+ {
+ swap(c, d, array);
+ d--;
+ }
+ c--;
+ }
+ if (b > c)
+ break;
+ swap(b, c, array);
+ b++;
+ c--;
+ }
+
+ // Swap pivot(s) back in place, the recurse on left and right sections.
+ hi = from + count;
+ int span;
+ span = Math.min(a - from, b - a);
+ vecswap(from, b - span, span, array);
+
+ span = Math.min(d - c, hi - d - 1);
+ vecswap(b, hi - span, span, array);
+
+ span = b - a;
+ if (span > 1)
+ qsort(array, from, span);
+
+ span = d - c;
+ if (span > 1)
+ qsort(array, hi - span, span);
+ }
+
+ /**
+ * Performs a stable sort on the elements, arranging them according to their
+ * natural order.
+ *
+ * @param a the char array to sort
+ */
+ public static void sort(char[] a)
+ {
+ qsort(a, 0, a.length);
+ }
+
+ /**
+ * Performs a stable sort on the elements, arranging them according to their
+ * natural order.
+ *
+ * @param a the char array to sort
+ * @param fromIndex the first index to sort (inclusive)
+ * @param toIndex the last index to sort (exclusive)
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0
+ * || toIndex > a.length
+ */
+ public static void sort(char[] a, int fromIndex, int toIndex)
+ {
+ if (fromIndex > toIndex)
+ throw new IllegalArgumentException();
+ if (fromIndex < 0)
+ throw new ArrayIndexOutOfBoundsException();
+ qsort(a, fromIndex, toIndex - fromIndex);
+ }
+
+ /**
+ * Finds the index of the median of three array elements.
+ *
+ * @param a the first index
+ * @param b the second index
+ * @param c the third index
+ * @param d the array
+ * @return the index (a, b, or c) which has the middle value of the three
+ */
+ private static int med3(int a, int b, int c, char[] d)
+ {
+ return (d[a] < d[b]
+ ? (d[b] < d[c] ? b : d[a] < d[c] ? c : a)
+ : (d[b] > d[c] ? b : d[a] > d[c] ? c : a));
+ }
+
+ /**
+ * Swaps the elements at two locations of an array
+ *
+ * @param i the first index
+ * @param j the second index
+ * @param a the array
+ */
+ private static void swap(int i, int j, char[] a)
+ {
+ char c = a[i];
+ a[i] = a[j];
+ a[j] = c;
+ }
+
+ /**
+ * Swaps two ranges of an array.
+ *
+ * @param i the first range start
+ * @param j the second range start
+ * @param n the element count
+ * @param a the array
+ */
+ private static void vecswap(int i, int j, int n, char[] a)
+ {
+ for ( ; n > 0; i++, j++, n--)
+ swap(i, j, a);
+ }
+
+ /**
+ * Performs a recursive modified quicksort.
+ *
+ * @param array the array to sort
+ * @param from the start index (inclusive)
+ * @param count the number of elements to sort
+ */
+ private static void qsort(char[] array, int from, int count)
+ {
+ // Use an insertion sort on small arrays.
+ if (count <= 7)
+ {
+ for (int i = from + 1; i < from + count; i++)
+ for (int j = i; j > from && array[j - 1] > array[j]; j--)
+ swap(j, j - 1, array);
+ return;
+ }
+
+ // Determine a good median element.
+ int mid = from + count / 2;
+ int lo = from;
+ int hi = from + count - 1;
+
+ if (count > 40)
+ { // big arrays, pseudomedian of 9
+ int s = count / 8;
+ lo = med3(lo, lo + s, lo + 2 * s, array);
+ mid = med3(mid - s, mid, mid + s, array);
+ hi = med3(hi - 2 * s, hi - s, hi, array);
+ }
+ mid = med3(lo, mid, hi, array);
+
+ int a, b, c, d;
+ int comp;
+
+ // Pull the median element out of the fray, and use it as a pivot.
+ swap(from, mid, array);
+ a = b = from;
+ c = d = from + count - 1;
+
+ // Repeatedly move b and c to each other, swapping elements so
+ // that all elements before index b are less than the pivot, and all
+ // elements after index c are greater than the pivot. a and b track
+ // the elements equal to the pivot.
+ while (true)
+ {
+ while (b <= c && (comp = array[b] - array[from]) <= 0)
+ {
+ if (comp == 0)
+ {
+ swap(a, b, array);
+ a++;
+ }
+ b++;
+ }
+ while (c >= b && (comp = array[c] - array[from]) >= 0)
+ {
+ if (comp == 0)
+ {
+ swap(c, d, array);
+ d--;
+ }
+ c--;
+ }
+ if (b > c)
+ break;
+ swap(b, c, array);
+ b++;
+ c--;
+ }
+
+ // Swap pivot(s) back in place, the recurse on left and right sections.
+ hi = from + count;
+ int span;
+ span = Math.min(a - from, b - a);
+ vecswap(from, b - span, span, array);
+
+ span = Math.min(d - c, hi - d - 1);
+ vecswap(b, hi - span, span, array);
+
+ span = b - a;
+ if (span > 1)
+ qsort(array, from, span);
+
+ span = d - c;
+ if (span > 1)
+ qsort(array, hi - span, span);
+ }
+
+ /**
+ * Performs a stable sort on the elements, arranging them according to their
+ * natural order.
+ *
+ * @param a the short array to sort
+ */
+ public static void sort(short[] a)
+ {
+ qsort(a, 0, a.length);
+ }
+
+ /**
+ * Performs a stable sort on the elements, arranging them according to their
+ * natural order.
+ *
+ * @param a the short array to sort
+ * @param fromIndex the first index to sort (inclusive)
+ * @param toIndex the last index to sort (exclusive)
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0
+ * || toIndex > a.length
+ */
+ public static void sort(short[] a, int fromIndex, int toIndex)
+ {
+ if (fromIndex > toIndex)
+ throw new IllegalArgumentException();
+ if (fromIndex < 0)
+ throw new ArrayIndexOutOfBoundsException();
+ qsort(a, fromIndex, toIndex - fromIndex);
+ }
+
+ /**
+ * Finds the index of the median of three array elements.
+ *
+ * @param a the first index
+ * @param b the second index
+ * @param c the third index
+ * @param d the array
+ * @return the index (a, b, or c) which has the middle value of the three
+ */
+ private static int med3(int a, int b, int c, short[] d)
+ {
+ return (d[a] < d[b]
+ ? (d[b] < d[c] ? b : d[a] < d[c] ? c : a)
+ : (d[b] > d[c] ? b : d[a] > d[c] ? c : a));
+ }
+
+ /**
+ * Swaps the elements at two locations of an array
+ *
+ * @param i the first index
+ * @param j the second index
+ * @param a the array
+ */
+ private static void swap(int i, int j, short[] a)
+ {
+ short c = a[i];
+ a[i] = a[j];
+ a[j] = c;
+ }
+
+ /**
+ * Swaps two ranges of an array.
+ *
+ * @param i the first range start
+ * @param j the second range start
+ * @param n the element count
+ * @param a the array
+ */
+ private static void vecswap(int i, int j, int n, short[] a)
+ {
+ for ( ; n > 0; i++, j++, n--)
+ swap(i, j, a);
+ }
+
+ /**
+ * Performs a recursive modified quicksort.
+ *
+ * @param array the array to sort
+ * @param from the start index (inclusive)
+ * @param count the number of elements to sort
+ */
+ private static void qsort(short[] array, int from, int count)
+ {
+ // Use an insertion sort on small arrays.
+ if (count <= 7)
+ {
+ for (int i = from + 1; i < from + count; i++)
+ for (int j = i; j > from && array[j - 1] > array[j]; j--)
+ swap(j, j - 1, array);
+ return;
+ }
+
+ // Determine a good median element.
+ int mid = from + count / 2;
+ int lo = from;
+ int hi = from + count - 1;
+
+ if (count > 40)
+ { // big arrays, pseudomedian of 9
+ int s = count / 8;
+ lo = med3(lo, lo + s, lo + 2 * s, array);
+ mid = med3(mid - s, mid, mid + s, array);
+ hi = med3(hi - 2 * s, hi - s, hi, array);
+ }
+ mid = med3(lo, mid, hi, array);
+
+ int a, b, c, d;
+ int comp;
+
+ // Pull the median element out of the fray, and use it as a pivot.
+ swap(from, mid, array);
+ a = b = from;
+ c = d = from + count - 1;
+
+ // Repeatedly move b and c to each other, swapping elements so
+ // that all elements before index b are less than the pivot, and all
+ // elements after index c are greater than the pivot. a and b track
+ // the elements equal to the pivot.
+ while (true)
+ {
+ while (b <= c && (comp = array[b] - array[from]) <= 0)
+ {
+ if (comp == 0)
+ {
+ swap(a, b, array);
+ a++;
+ }
+ b++;
+ }
+ while (c >= b && (comp = array[c] - array[from]) >= 0)
+ {
+ if (comp == 0)
+ {
+ swap(c, d, array);
+ d--;
+ }
+ c--;
+ }
+ if (b > c)
+ break;
+ swap(b, c, array);
+ b++;
+ c--;
+ }
+
+ // Swap pivot(s) back in place, the recurse on left and right sections.
+ hi = from + count;
+ int span;
+ span = Math.min(a - from, b - a);
+ vecswap(from, b - span, span, array);
+
+ span = Math.min(d - c, hi - d - 1);
+ vecswap(b, hi - span, span, array);
+
+ span = b - a;
+ if (span > 1)
+ qsort(array, from, span);
+
+ span = d - c;
+ if (span > 1)
+ qsort(array, hi - span, span);
+ }
+
+ /**
+ * Performs a stable sort on the elements, arranging them according to their
+ * natural order.
+ *
+ * @param a the int array to sort
+ */
+ public static void sort(int[] a)
+ {
+ qsort(a, 0, a.length);
+ }
+
+ /**
+ * Performs a stable sort on the elements, arranging them according to their
+ * natural order.
+ *
+ * @param a the int array to sort
+ * @param fromIndex the first index to sort (inclusive)
+ * @param toIndex the last index to sort (exclusive)
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0
+ * || toIndex > a.length
+ */
+ public static void sort(int[] a, int fromIndex, int toIndex)
+ {
+ if (fromIndex > toIndex)
+ throw new IllegalArgumentException();
+ if (fromIndex < 0)
+ throw new ArrayIndexOutOfBoundsException();
+ qsort(a, fromIndex, toIndex - fromIndex);
+ }
+
+ /**
+ * Finds the index of the median of three array elements.
+ *
+ * @param a the first index
+ * @param b the second index
+ * @param c the third index
+ * @param d the array
+ * @return the index (a, b, or c) which has the middle value of the three
+ */
+ private static int med3(int a, int b, int c, int[] d)
+ {
+ return (d[a] < d[b]
+ ? (d[b] < d[c] ? b : d[a] < d[c] ? c : a)
+ : (d[b] > d[c] ? b : d[a] > d[c] ? c : a));
+ }
+
+ /**
+ * Swaps the elements at two locations of an array
+ *
+ * @param i the first index
+ * @param j the second index
+ * @param a the array
+ */
+ private static void swap(int i, int j, int[] a)
+ {
+ int c = a[i];
+ a[i] = a[j];
+ a[j] = c;
+ }
+
+ /**
+ * Swaps two ranges of an array.
+ *
+ * @param i the first range start
+ * @param j the second range start
+ * @param n the element count
+ * @param a the array
+ */
+ private static void vecswap(int i, int j, int n, int[] a)
+ {
+ for ( ; n > 0; i++, j++, n--)
+ swap(i, j, a);
+ }
+
+ /**
+ * Compares two integers in natural order, since a - b is inadequate.
+ *
+ * @param a the first int
+ * @param b the second int
+ * @return < 0, 0, or > 0 accorting to the comparison
+ */
+ private static int compare(int a, int b)
+ {
+ return a < b ? -1 : a == b ? 0 : 1;
+ }
+
+ /**
+ * Performs a recursive modified quicksort.
+ *
+ * @param array the array to sort
+ * @param from the start index (inclusive)
+ * @param count the number of elements to sort
+ */
+ private static void qsort(int[] array, int from, int count)
+ {
+ // Use an insertion sort on small arrays.
+ if (count <= 7)
+ {
+ for (int i = from + 1; i < from + count; i++)
+ for (int j = i; j > from && array[j - 1] > array[j]; j--)
+ swap(j, j - 1, array);
+ return;
+ }
+
+ // Determine a good median element.
+ int mid = from + count / 2;
+ int lo = from;
+ int hi = from + count - 1;
+
+ if (count > 40)
+ { // big arrays, pseudomedian of 9
+ int s = count / 8;
+ lo = med3(lo, lo + s, lo + 2 * s, array);
+ mid = med3(mid - s, mid, mid + s, array);
+ hi = med3(hi - 2 * s, hi - s, hi, array);
+ }
+ mid = med3(lo, mid, hi, array);
+
+ int a, b, c, d;
+ int comp;
+
+ // Pull the median element out of the fray, and use it as a pivot.
+ swap(from, mid, array);
+ a = b = from;
+ c = d = from + count - 1;
+
+ // Repeatedly move b and c to each other, swapping elements so
+ // that all elements before index b are less than the pivot, and all
+ // elements after index c are greater than the pivot. a and b track
+ // the elements equal to the pivot.
+ while (true)
+ {
+ while (b <= c && (comp = compare(array[b], array[from])) <= 0)
+ {
+ if (comp == 0)
+ {
+ swap(a, b, array);
+ a++;
+ }
+ b++;
+ }
+ while (c >= b && (comp = compare(array[c], array[from])) >= 0)
+ {
+ if (comp == 0)
+ {
+ swap(c, d, array);
+ d--;
+ }
+ c--;
+ }
+ if (b > c)
+ break;
+ swap(b, c, array);
+ b++;
+ c--;
+ }
+
+ // Swap pivot(s) back in place, the recurse on left and right sections.
+ hi = from + count;
+ int span;
+ span = Math.min(a - from, b - a);
+ vecswap(from, b - span, span, array);
+
+ span = Math.min(d - c, hi - d - 1);
+ vecswap(b, hi - span, span, array);
+
+ span = b - a;
+ if (span > 1)
+ qsort(array, from, span);
+
+ span = d - c;
+ if (span > 1)
+ qsort(array, hi - span, span);
+ }
+
+ /**
+ * Performs a stable sort on the elements, arranging them according to their
+ * natural order.
+ *
+ * @param a the long array to sort
+ */
+ public static void sort(long[] a)
+ {
+ qsort(a, 0, a.length);
+ }
+
+ /**
+ * Performs a stable sort on the elements, arranging them according to their
+ * natural order.
+ *
+ * @param a the long array to sort
+ * @param fromIndex the first index to sort (inclusive)
+ * @param toIndex the last index to sort (exclusive)
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0
+ * || toIndex > a.length
+ */
+ public static void sort(long[] a, int fromIndex, int toIndex)
+ {
+ if (fromIndex > toIndex)
+ throw new IllegalArgumentException();
+ if (fromIndex < 0)
+ throw new ArrayIndexOutOfBoundsException();
+ qsort(a, fromIndex, toIndex - fromIndex);
+ }
+
+ /**
+ * Finds the index of the median of three array elements.
+ *
+ * @param a the first index
+ * @param b the second index
+ * @param c the third index
+ * @param d the array
+ * @return the index (a, b, or c) which has the middle value of the three
+ */
+ private static int med3(int a, int b, int c, long[] d)
+ {
+ return (d[a] < d[b]
+ ? (d[b] < d[c] ? b : d[a] < d[c] ? c : a)
+ : (d[b] > d[c] ? b : d[a] > d[c] ? c : a));
+ }
+
+ /**
+ * Swaps the elements at two locations of an array
+ *
+ * @param i the first index
+ * @param j the second index
+ * @param a the array
+ */
+ private static void swap(int i, int j, long[] a)
+ {
+ long c = a[i];
+ a[i] = a[j];
+ a[j] = c;
+ }
+
+ /**
+ * Swaps two ranges of an array.
+ *
+ * @param i the first range start
+ * @param j the second range start
+ * @param n the element count
+ * @param a the array
+ */
+ private static void vecswap(int i, int j, int n, long[] a)
+ {
+ for ( ; n > 0; i++, j++, n--)
+ swap(i, j, a);
+ }
+
+ /**
+ * Compares two longs in natural order, since a - b is inadequate.
+ *
+ * @param a the first long
+ * @param b the second long
+ * @return < 0, 0, or > 0 accorting to the comparison
+ */
+ private static int compare(long a, long b)
+ {
+ return a < b ? -1 : a == b ? 0 : 1;
+ }
+
+ /**
+ * Performs a recursive modified quicksort.
+ *
+ * @param array the array to sort
+ * @param from the start index (inclusive)
+ * @param count the number of elements to sort
+ */
+ private static void qsort(long[] array, int from, int count)
+ {
+ // Use an insertion sort on small arrays.
+ if (count <= 7)
+ {
+ for (int i = from + 1; i < from + count; i++)
+ for (int j = i; j > from && array[j - 1] > array[j]; j--)
+ swap(j, j - 1, array);
+ return;
+ }
+
+ // Determine a good median element.
+ int mid = from + count / 2;
+ int lo = from;
+ int hi = from + count - 1;
+
+ if (count > 40)
+ { // big arrays, pseudomedian of 9
+ int s = count / 8;
+ lo = med3(lo, lo + s, lo + 2 * s, array);
+ mid = med3(mid - s, mid, mid + s, array);
+ hi = med3(hi - 2 * s, hi - s, hi, array);
+ }
+ mid = med3(lo, mid, hi, array);
+
+ int a, b, c, d;
+ int comp;
+
+ // Pull the median element out of the fray, and use it as a pivot.
+ swap(from, mid, array);
+ a = b = from;
+ c = d = from + count - 1;
+
+ // Repeatedly move b and c to each other, swapping elements so
+ // that all elements before index b are less than the pivot, and all
+ // elements after index c are greater than the pivot. a and b track
+ // the elements equal to the pivot.
+ while (true)
+ {
+ while (b <= c && (comp = compare(array[b], array[from])) <= 0)
+ {
+ if (comp == 0)
+ {
+ swap(a, b, array);
+ a++;
+ }
+ b++;
+ }
+ while (c >= b && (comp = compare(array[c], array[from])) >= 0)
+ {
+ if (comp == 0)
+ {
+ swap(c, d, array);
+ d--;
+ }
+ c--;
+ }
+ if (b > c)
+ break;
+ swap(b, c, array);
+ b++;
+ c--;
+ }
+
+ // Swap pivot(s) back in place, the recurse on left and right sections.
+ hi = from + count;
+ int span;
+ span = Math.min(a - from, b - a);
+ vecswap(from, b - span, span, array);
+
+ span = Math.min(d - c, hi - d - 1);
+ vecswap(b, hi - span, span, array);
+
+ span = b - a;
+ if (span > 1)
+ qsort(array, from, span);
+
+ span = d - c;
+ if (span > 1)
+ qsort(array, hi - span, span);
+ }
+
+ /**
+ * Performs a stable sort on the elements, arranging them according to their
+ * natural order.
+ *
+ * @param a the float array to sort
+ */
+ public static void sort(float[] a)
+ {
+ qsort(a, 0, a.length);
+ }
+
+ /**
+ * Performs a stable sort on the elements, arranging them according to their
+ * natural order.
+ *
+ * @param a the float array to sort
+ * @param fromIndex the first index to sort (inclusive)
+ * @param toIndex the last index to sort (exclusive)
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0
+ * || toIndex > a.length
+ */
+ public static void sort(float[] a, int fromIndex, int toIndex)
+ {
+ if (fromIndex > toIndex)
+ throw new IllegalArgumentException();
+ if (fromIndex < 0)
+ throw new ArrayIndexOutOfBoundsException();
+ qsort(a, fromIndex, toIndex - fromIndex);
+ }
+
+ /**
+ * Finds the index of the median of three array elements.
+ *
+ * @param a the first index
+ * @param b the second index
+ * @param c the third index
+ * @param d the array
+ * @return the index (a, b, or c) which has the middle value of the three
+ */
+ private static int med3(int a, int b, int c, float[] d)
+ {
+ return (Float.compare(d[a], d[b]) < 0
+ ? (Float.compare(d[b], d[c]) < 0 ? b
+ : Float.compare(d[a], d[c]) < 0 ? c : a)
+ : (Float.compare(d[b], d[c]) > 0 ? b
+ : Float.compare(d[a], d[c]) > 0 ? c : a));
+ }
+
+ /**
+ * Swaps the elements at two locations of an array
+ *
+ * @param i the first index
+ * @param j the second index
+ * @param a the array
+ */
+ private static void swap(int i, int j, float[] a)
+ {
+ float c = a[i];
+ a[i] = a[j];
+ a[j] = c;
+ }
+
+ /**
+ * Swaps two ranges of an array.
+ *
+ * @param i the first range start
+ * @param j the second range start
+ * @param n the element count
+ * @param a the array
+ */
+ private static void vecswap(int i, int j, int n, float[] a)
+ {
+ for ( ; n > 0; i++, j++, n--)
+ swap(i, j, a);
+ }
+
+ /**
+ * Performs a recursive modified quicksort.
+ *
+ * @param array the array to sort
+ * @param from the start index (inclusive)
+ * @param count the number of elements to sort
+ */
+ private static void qsort(float[] array, int from, int count)
+ {
+ // Use an insertion sort on small arrays.
+ if (count <= 7)
+ {
+ for (int i = from + 1; i < from + count; i++)
+ for (int j = i;
+ j > from && Float.compare(array[j - 1], array[j]) > 0;
+ j--)
+ {
+ swap(j, j - 1, array);
+ }
+ return;
+ }
+
+ // Determine a good median element.
+ int mid = from + count / 2;
+ int lo = from;
+ int hi = from + count - 1;
+
+ if (count > 40)
+ { // big arrays, pseudomedian of 9
+ int s = count / 8;
+ lo = med3(lo, lo + s, lo + 2 * s, array);
+ mid = med3(mid - s, mid, mid + s, array);
+ hi = med3(hi - 2 * s, hi - s, hi, array);
+ }
+ mid = med3(lo, mid, hi, array);
+
+ int a, b, c, d;
+ int comp;
+
+ // Pull the median element out of the fray, and use it as a pivot.
+ swap(from, mid, array);
+ a = b = from;
+ c = d = from + count - 1;
+
+ // Repeatedly move b and c to each other, swapping elements so
+ // that all elements before index b are less than the pivot, and all
+ // elements after index c are greater than the pivot. a and b track
+ // the elements equal to the pivot.
+ while (true)
+ {
+ while (b <= c && (comp = Float.compare(array[b], array[from])) <= 0)
+ {
+ if (comp == 0)
+ {
+ swap(a, b, array);
+ a++;
+ }
+ b++;
+ }
+ while (c >= b && (comp = Float.compare(array[c], array[from])) >= 0)
+ {
+ if (comp == 0)
+ {
+ swap(c, d, array);
+ d--;
+ }
+ c--;
+ }
+ if (b > c)
+ break;
+ swap(b, c, array);
+ b++;
+ c--;
+ }
+
+ // Swap pivot(s) back in place, the recurse on left and right sections.
+ hi = from + count;
+ int span;
+ span = Math.min(a - from, b - a);
+ vecswap(from, b - span, span, array);
+
+ span = Math.min(d - c, hi - d - 1);
+ vecswap(b, hi - span, span, array);
+
+ span = b - a;
+ if (span > 1)
+ qsort(array, from, span);
+
+ span = d - c;
+ if (span > 1)
+ qsort(array, hi - span, span);
+ }
+
+ /**
+ * Performs a stable sort on the elements, arranging them according to their
+ * natural order.
+ *
+ * @param a the double array to sort
+ */
+ public static void sort(double[] a)
+ {
+ qsort(a, 0, a.length);
+ }
+
+ /**
+ * Performs a stable sort on the elements, arranging them according to their
+ * natural order.
+ *
+ * @param a the double array to sort
+ * @param fromIndex the first index to sort (inclusive)
+ * @param toIndex the last index to sort (exclusive)
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0
+ * || toIndex > a.length
+ */
+ public static void sort(double[] a, int fromIndex, int toIndex)
+ {
+ if (fromIndex > toIndex)
+ throw new IllegalArgumentException();
+ if (fromIndex < 0)
+ throw new ArrayIndexOutOfBoundsException();
+ qsort(a, fromIndex, toIndex - fromIndex);
+ }
+
+ /**
+ * Finds the index of the median of three array elements.
+ *
+ * @param a the first index
+ * @param b the second index
+ * @param c the third index
+ * @param d the array
+ * @return the index (a, b, or c) which has the middle value of the three
+ */
+ private static int med3(int a, int b, int c, double[] d)
+ {
+ return (Double.compare(d[a], d[b]) < 0
+ ? (Double.compare(d[b], d[c]) < 0 ? b
+ : Double.compare(d[a], d[c]) < 0 ? c : a)
+ : (Double.compare(d[b], d[c]) > 0 ? b
+ : Double.compare(d[a], d[c]) > 0 ? c : a));
+ }
+
+ /**
+ * Swaps the elements at two locations of an array
+ *
+ * @param i the first index
+ * @param j the second index
+ * @param a the array
+ */
+ private static void swap(int i, int j, double[] a)
+ {
+ double c = a[i];
+ a[i] = a[j];
+ a[j] = c;
+ }
+
+ /**
+ * Swaps two ranges of an array.
+ *
+ * @param i the first range start
+ * @param j the second range start
+ * @param n the element count
+ * @param a the array
+ */
+ private static void vecswap(int i, int j, int n, double[] a)
+ {
+ for ( ; n > 0; i++, j++, n--)
+ swap(i, j, a);
+ }
+
+ /**
+ * Performs a recursive modified quicksort.
+ *
+ * @param array the array to sort
+ * @param from the start index (inclusive)
+ * @param count the number of elements to sort
+ */
+ private static void qsort(double[] array, int from, int count)
+ {
+ // Use an insertion sort on small arrays.
+ if (count <= 7)
+ {
+ for (int i = from + 1; i < from + count; i++)
+ for (int j = i;
+ j > from && Double.compare(array[j - 1], array[j]) > 0;
+ j--)
+ {
+ swap(j, j - 1, array);
+ }
+ return;
+ }
+
+ // Determine a good median element.
+ int mid = from + count / 2;
+ int lo = from;
+ int hi = from + count - 1;
+
+ if (count > 40)
+ { // big arrays, pseudomedian of 9
+ int s = count / 8;
+ lo = med3(lo, lo + s, lo + 2 * s, array);
+ mid = med3(mid - s, mid, mid + s, array);
+ hi = med3(hi - 2 * s, hi - s, hi, array);
+ }
+ mid = med3(lo, mid, hi, array);
+
+ int a, b, c, d;
+ int comp;
+
+ // Pull the median element out of the fray, and use it as a pivot.
+ swap(from, mid, array);
+ a = b = from;
+ c = d = from + count - 1;
+
+ // Repeatedly move b and c to each other, swapping elements so
+ // that all elements before index b are less than the pivot, and all
+ // elements after index c are greater than the pivot. a and b track
+ // the elements equal to the pivot.
+ while (true)
+ {
+ while (b <= c && (comp = Double.compare(array[b], array[from])) <= 0)
+ {
+ if (comp == 0)
+ {
+ swap(a, b, array);
+ a++;
+ }
+ b++;
+ }
+ while (c >= b && (comp = Double.compare(array[c], array[from])) >= 0)
+ {
+ if (comp == 0)
+ {
+ swap(c, d, array);
+ d--;
+ }
+ c--;
+ }
+ if (b > c)
+ break;
+ swap(b, c, array);
+ b++;
+ c--;
+ }
+
+ // Swap pivot(s) back in place, the recurse on left and right sections.
+ hi = from + count;
+ int span;
+ span = Math.min(a - from, b - a);
+ vecswap(from, b - span, span, array);
+
+ span = Math.min(d - c, hi - d - 1);
+ vecswap(b, hi - span, span, array);
+
+ span = b - a;
+ if (span > 1)
+ qsort(array, from, span);
+
+ span = d - c;
+ if (span > 1)
+ qsort(array, hi - span, span);
+ }
+
+ /**
+ * Sort an array of Objects according to their natural ordering. The sort is
+ * guaranteed to be stable, that is, equal elements will not be reordered.
+ * The sort algorithm is a mergesort with the merge omitted if the last
+ * element of one half comes before the first element of the other half. This
+ * algorithm gives guaranteed O(n*log(n)) time, at the expense of making a
+ * copy of the array.
+ *
+ * @param a the array to be sorted
+ * @throws ClassCastException if any two elements are not mutually
+ * comparable
+ * @throws NullPointerException if an element is null (since
+ * null.compareTo cannot work)
+ * @see Comparable
+ */
+ public static void sort(Object[] a)
+ {
+ sort(a, 0, a.length, null);
+ }
+
+ /**
+ * Sort an array of Objects according to a Comparator. The sort is
+ * guaranteed to be stable, that is, equal elements will not be reordered.
+ * The sort algorithm is a mergesort with the merge omitted if the last
+ * element of one half comes before the first element of the other half. This
+ * algorithm gives guaranteed O(n*log(n)) time, at the expense of making a
+ * copy of the array.
+ *
+ * @param a the array to be sorted
+ * @param c a Comparator to use in sorting the array; or null to indicate
+ * the elements' natural order
+ * @throws ClassCastException if any two elements are not mutually
+ * comparable by the Comparator provided
+ * @throws NullPointerException if a null element is compared with natural
+ * ordering (only possible when c is null)
+ */
+ public static <T> void sort(T[] a, Comparator<? super T> c)
+ {
+ sort(a, 0, a.length, c);
+ }
+
+ /**
+ * Sort an array of Objects according to their natural ordering. The sort is
+ * guaranteed to be stable, that is, equal elements will not be reordered.
+ * The sort algorithm is a mergesort with the merge omitted if the last
+ * element of one half comes before the first element of the other half. This
+ * algorithm gives guaranteed O(n*log(n)) time, at the expense of making a
+ * copy of the array.
+ *
+ * @param a the array to be sorted
+ * @param fromIndex the index of the first element to be sorted
+ * @param toIndex the index of the last element to be sorted plus one
+ * @throws ClassCastException if any two elements are not mutually
+ * comparable
+ * @throws NullPointerException if an element is null (since
+ * null.compareTo cannot work)
+ * @throws ArrayIndexOutOfBoundsException if fromIndex and toIndex
+ * are not in range.
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ */
+ public static void sort(Object[] a, int fromIndex, int toIndex)
+ {
+ sort(a, fromIndex, toIndex, null);
+ }
+
+ /**
+ * Sort an array of Objects according to a Comparator. The sort is
+ * guaranteed to be stable, that is, equal elements will not be reordered.
+ * The sort algorithm is a mergesort with the merge omitted if the last
+ * element of one half comes before the first element of the other half. This
+ * algorithm gives guaranteed O(n*log(n)) time, at the expense of making a
+ * copy of the array.
+ *
+ * @param a the array to be sorted
+ * @param fromIndex the index of the first element to be sorted
+ * @param toIndex the index of the last element to be sorted plus one
+ * @param c a Comparator to use in sorting the array; or null to indicate
+ * the elements' natural order
+ * @throws ClassCastException if any two elements are not mutually
+ * comparable by the Comparator provided
+ * @throws ArrayIndexOutOfBoundsException if fromIndex and toIndex
+ * are not in range.
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws NullPointerException if a null element is compared with natural
+ * ordering (only possible when c is null)
+ */
+ public static <T> void sort(T[] a, int fromIndex, int toIndex,
+ Comparator<? super T> c)
+ {
+ if (fromIndex > toIndex)
+ throw new IllegalArgumentException("fromIndex " + fromIndex
+ + " > toIndex " + toIndex);
+ if (fromIndex < 0)
+ throw new ArrayIndexOutOfBoundsException();
+
+ // In general, the code attempts to be simple rather than fast, the
+ // idea being that a good optimising JIT will be able to optimise it
+ // better than I can, and if I try it will make it more confusing for
+ // the JIT. First presort the array in chunks of length 6 with insertion
+ // sort. A mergesort would give too much overhead for this length.
+ for (int chunk = fromIndex; chunk < toIndex; chunk += 6)
+ {
+ int end = Math.min(chunk + 6, toIndex);
+ for (int i = chunk + 1; i < end; i++)
+ {
+ if (Collections.compare(a[i - 1], a[i], c) > 0)
+ {
+ // not already sorted
+ int j = i;
+ T elem = a[j];
+ do
+ {
+ a[j] = a[j - 1];
+ j--;
+ }
+ while (j > chunk
+ && Collections.compare(a[j - 1], elem, c) > 0);
+ a[j] = elem;
+ }
+ }
+ }
+
+ int len = toIndex - fromIndex;
+ // If length is smaller or equal 6 we are done.
+ if (len <= 6)
+ return;
+
+ T[] src = a;
+ T[] dest = (T[]) new Object[len];
+ T[] t = null; // t is used for swapping src and dest
+
+ // The difference of the fromIndex of the src and dest array.
+ int srcDestDiff = -fromIndex;
+
+ // The merges are done in this loop
+ for (int size = 6; size < len; size <<= 1)
+ {
+ for (int start = fromIndex; start < toIndex; start += size << 1)
+ {
+ // mid is the start of the second sublist;
+ // end the start of the next sublist (or end of array).
+ int mid = start + size;
+ int end = Math.min(toIndex, mid + size);
+
+ // The second list is empty or the elements are already in
+ // order - no need to merge
+ if (mid >= end
+ || Collections.compare(src[mid - 1], src[mid], c) <= 0)
+ {
+ System.arraycopy(src, start,
+ dest, start + srcDestDiff, end - start);
+
+ // The two halves just need swapping - no need to merge
+ }
+ else if (Collections.compare(src[start], src[end - 1], c) > 0)
+ {
+ System.arraycopy(src, start,
+ dest, end - size + srcDestDiff, size);
+ System.arraycopy(src, mid,
+ dest, start + srcDestDiff, end - mid);
+
+ }
+ else
+ {
+ // Declare a lot of variables to save repeating
+ // calculations. Hopefully a decent JIT will put these
+ // in registers and make this fast
+ int p1 = start;
+ int p2 = mid;
+ int i = start + srcDestDiff;
+
+ // The main merge loop; terminates as soon as either
+ // half is ended
+ while (p1 < mid && p2 < end)
+ {
+ dest[i++] =
+ src[(Collections.compare(src[p1], src[p2], c) <= 0
+ ? p1++ : p2++)];
+ }
+
+ // Finish up by copying the remainder of whichever half
+ // wasn't finished.
+ if (p1 < mid)
+ System.arraycopy(src, p1, dest, i, mid - p1);
+ else
+ System.arraycopy(src, p2, dest, i, end - p2);
+ }
+ }
+ // swap src and dest ready for the next merge
+ t = src;
+ src = dest;
+ dest = t;
+ fromIndex += srcDestDiff;
+ toIndex += srcDestDiff;
+ srcDestDiff = -srcDestDiff;
+ }
+
+ // make sure the result ends up back in the right place. Note
+ // that src and dest may have been swapped above, so src
+ // contains the sorted array.
+ if (src != a)
+ {
+ // Note that fromIndex == 0.
+ System.arraycopy(src, 0, a, srcDestDiff, toIndex);
+ }
+ }
+
+ /**
+ * Returns a list "view" of the specified array. This method is intended to
+ * make it easy to use the Collections API with existing array-based APIs and
+ * programs. Changes in the list or the array show up in both places. The
+ * list does not support element addition or removal, but does permit
+ * value modification. The returned list implements both Serializable and
+ * RandomAccess.
+ *
+ * @param a the array to return a view of (<code>null</code> not permitted)
+ * @return a fixed-size list, changes to which "write through" to the array
+ *
+ * @throws NullPointerException if <code>a</code> is <code>null</code>.
+ * @see Serializable
+ * @see RandomAccess
+ * @see Arrays.ArrayList
+ */
+ public static <T> List<T> asList(final T... a)
+ {
+ return new Arrays.ArrayList(a);
+ }
+
+ /**
+ * Returns the hashcode of an array of long numbers. If two arrays
+ * are equal, according to <code>equals()</code>, they should have the
+ * same hashcode. The hashcode returned by the method is equal to that
+ * obtained by the corresponding <code>List</code> object. This has the same
+ * data, but represents longs in their wrapper class, <code>Long</code>.
+ * For <code>null</code>, 0 is returned.
+ *
+ * @param v an array of long numbers for which the hash code should be
+ * computed.
+ * @return the hash code of the array, or 0 if null was given.
+ * @since 1.5
+ */
+ public static int hashCode(long[] v)
+ {
+ if (v == null)
+ return 0;
+ int result = 1;
+ for (int i = 0; i < v.length; ++i)
+ {
+ int elt = (int) (v[i] ^ (v[i] >>> 32));
+ result = 31 * result + elt;
+ }
+ return result;
+ }
+
+ /**
+ * Returns the hashcode of an array of integer numbers. If two arrays
+ * are equal, according to <code>equals()</code>, they should have the
+ * same hashcode. The hashcode returned by the method is equal to that
+ * obtained by the corresponding <code>List</code> object. This has the same
+ * data, but represents ints in their wrapper class, <code>Integer</code>.
+ * For <code>null</code>, 0 is returned.
+ *
+ * @param v an array of integer numbers for which the hash code should be
+ * computed.
+ * @return the hash code of the array, or 0 if null was given.
+ * @since 1.5
+ */
+ public static int hashCode(int[] v)
+ {
+ if (v == null)
+ return 0;
+ int result = 1;
+ for (int i = 0; i < v.length; ++i)
+ result = 31 * result + v[i];
+ return result;
+ }
+
+ /**
+ * Returns the hashcode of an array of short numbers. If two arrays
+ * are equal, according to <code>equals()</code>, they should have the
+ * same hashcode. The hashcode returned by the method is equal to that
+ * obtained by the corresponding <code>List</code> object. This has the same
+ * data, but represents shorts in their wrapper class, <code>Short</code>.
+ * For <code>null</code>, 0 is returned.
+ *
+ * @param v an array of short numbers for which the hash code should be
+ * computed.
+ * @return the hash code of the array, or 0 if null was given.
+ * @since 1.5
+ */
+ public static int hashCode(short[] v)
+ {
+ if (v == null)
+ return 0;
+ int result = 1;
+ for (int i = 0; i < v.length; ++i)
+ result = 31 * result + v[i];
+ return result;
+ }
+
+ /**
+ * Returns the hashcode of an array of characters. If two arrays
+ * are equal, according to <code>equals()</code>, they should have the
+ * same hashcode. The hashcode returned by the method is equal to that
+ * obtained by the corresponding <code>List</code> object. This has the same
+ * data, but represents chars in their wrapper class, <code>Character</code>.
+ * For <code>null</code>, 0 is returned.
+ *
+ * @param v an array of characters for which the hash code should be
+ * computed.
+ * @return the hash code of the array, or 0 if null was given.
+ * @since 1.5
+ */
+ public static int hashCode(char[] v)
+ {
+ if (v == null)
+ return 0;
+ int result = 1;
+ for (int i = 0; i < v.length; ++i)
+ result = 31 * result + v[i];
+ return result;
+ }
+
+ /**
+ * Returns the hashcode of an array of bytes. If two arrays
+ * are equal, according to <code>equals()</code>, they should have the
+ * same hashcode. The hashcode returned by the method is equal to that
+ * obtained by the corresponding <code>List</code> object. This has the same
+ * data, but represents bytes in their wrapper class, <code>Byte</code>.
+ * For <code>null</code>, 0 is returned.
+ *
+ * @param v an array of bytes for which the hash code should be
+ * computed.
+ * @return the hash code of the array, or 0 if null was given.
+ * @since 1.5
+ */
+ public static int hashCode(byte[] v)
+ {
+ if (v == null)
+ return 0;
+ int result = 1;
+ for (int i = 0; i < v.length; ++i)
+ result = 31 * result + v[i];
+ return result;
+ }
+
+ /**
+ * Returns the hashcode of an array of booleans. If two arrays
+ * are equal, according to <code>equals()</code>, they should have the
+ * same hashcode. The hashcode returned by the method is equal to that
+ * obtained by the corresponding <code>List</code> object. This has the same
+ * data, but represents booleans in their wrapper class,
+ * <code>Boolean</code>. For <code>null</code>, 0 is returned.
+ *
+ * @param v an array of booleans for which the hash code should be
+ * computed.
+ * @return the hash code of the array, or 0 if null was given.
+ * @since 1.5
+ */
+ public static int hashCode(boolean[] v)
+ {
+ if (v == null)
+ return 0;
+ int result = 1;
+ for (int i = 0; i < v.length; ++i)
+ result = 31 * result + (v[i] ? 1231 : 1237);
+ return result;
+ }
+
+ /**
+ * Returns the hashcode of an array of floats. If two arrays
+ * are equal, according to <code>equals()</code>, they should have the
+ * same hashcode. The hashcode returned by the method is equal to that
+ * obtained by the corresponding <code>List</code> object. This has the same
+ * data, but represents floats in their wrapper class, <code>Float</code>.
+ * For <code>null</code>, 0 is returned.
+ *
+ * @param v an array of floats for which the hash code should be
+ * computed.
+ * @return the hash code of the array, or 0 if null was given.
+ * @since 1.5
+ */
+ public static int hashCode(float[] v)
+ {
+ if (v == null)
+ return 0;
+ int result = 1;
+ for (int i = 0; i < v.length; ++i)
+ result = 31 * result + Float.floatToIntBits(v[i]);
+ return result;
+ }
+
+ /**
+ * Returns the hashcode of an array of doubles. If two arrays
+ * are equal, according to <code>equals()</code>, they should have the
+ * same hashcode. The hashcode returned by the method is equal to that
+ * obtained by the corresponding <code>List</code> object. This has the same
+ * data, but represents doubles in their wrapper class, <code>Double</code>.
+ * For <code>null</code>, 0 is returned.
+ *
+ * @param v an array of doubles for which the hash code should be
+ * computed.
+ * @return the hash code of the array, or 0 if null was given.
+ * @since 1.5
+ */
+ public static int hashCode(double[] v)
+ {
+ if (v == null)
+ return 0;
+ int result = 1;
+ for (int i = 0; i < v.length; ++i)
+ {
+ long l = Double.doubleToLongBits(v[i]);
+ int elt = (int) (l ^ (l >>> 32));
+ result = 31 * result + elt;
+ }
+ return result;
+ }
+
+ /**
+ * Returns the hashcode of an array of objects. If two arrays
+ * are equal, according to <code>equals()</code>, they should have the
+ * same hashcode. The hashcode returned by the method is equal to that
+ * obtained by the corresponding <code>List</code> object.
+ * For <code>null</code>, 0 is returned.
+ *
+ * @param v an array of integer numbers for which the hash code should be
+ * computed.
+ * @return the hash code of the array, or 0 if null was given.
+ * @since 1.5
+ */
+ public static int hashCode(Object[] v)
+ {
+ if (v == null)
+ return 0;
+ int result = 1;
+ for (int i = 0; i < v.length; ++i)
+ {
+ int elt = v[i] == null ? 0 : v[i].hashCode();
+ result = 31 * result + elt;
+ }
+ return result;
+ }
+
+ public static int deepHashCode(Object[] v)
+ {
+ if (v == null)
+ return 0;
+ int result = 1;
+ for (int i = 0; i < v.length; ++i)
+ {
+ int elt;
+ if (v[i] == null)
+ elt = 0;
+ else if (v[i] instanceof boolean[])
+ elt = hashCode((boolean[]) v[i]);
+ else if (v[i] instanceof byte[])
+ elt = hashCode((byte[]) v[i]);
+ else if (v[i] instanceof char[])
+ elt = hashCode((char[]) v[i]);
+ else if (v[i] instanceof short[])
+ elt = hashCode((short[]) v[i]);
+ else if (v[i] instanceof int[])
+ elt = hashCode((int[]) v[i]);
+ else if (v[i] instanceof long[])
+ elt = hashCode((long[]) v[i]);
+ else if (v[i] instanceof float[])
+ elt = hashCode((float[]) v[i]);
+ else if (v[i] instanceof double[])
+ elt = hashCode((double[]) v[i]);
+ else if (v[i] instanceof Object[])
+ elt = hashCode((Object[]) v[i]);
+ else
+ elt = v[i].hashCode();
+ result = 31 * result + elt;
+ }
+ return result;
+ }
+
+ /** @since 1.5 */
+ public static boolean deepEquals(Object[] v1, Object[] v2)
+ {
+ if (v1 == null)
+ return v2 == null;
+ if (v2 == null || v1.length != v2.length)
+ return false;
+
+ for (int i = 0; i < v1.length; ++i)
+ {
+ Object e1 = v1[i];
+ Object e2 = v2[i];
+
+ if (e1 == e2)
+ continue;
+ if (e1 == null || e2 == null)
+ return false;
+
+ boolean check;
+ if (e1 instanceof boolean[] && e2 instanceof boolean[])
+ check = equals((boolean[]) e1, (boolean[]) e2);
+ else if (e1 instanceof byte[] && e2 instanceof byte[])
+ check = equals((byte[]) e1, (byte[]) e2);
+ else if (e1 instanceof char[] && e2 instanceof char[])
+ check = equals((char[]) e1, (char[]) e2);
+ else if (e1 instanceof short[] && e2 instanceof short[])
+ check = equals((short[]) e1, (short[]) e2);
+ else if (e1 instanceof int[] && e2 instanceof int[])
+ check = equals((int[]) e1, (int[]) e2);
+ else if (e1 instanceof long[] && e2 instanceof long[])
+ check = equals((long[]) e1, (long[]) e2);
+ else if (e1 instanceof float[] && e2 instanceof float[])
+ check = equals((float[]) e1, (float[]) e2);
+ else if (e1 instanceof double[] && e2 instanceof double[])
+ check = equals((double[]) e1, (double[]) e2);
+ else if (e1 instanceof Object[] && e2 instanceof Object[])
+ check = equals((Object[]) e1, (Object[]) e2);
+ else
+ check = e1.equals(e2);
+ if (! check)
+ return false;
+ }
+
+ return true;
+ }
+
+ /**
+ * Returns a String representation of the argument array. Returns "null"
+ * if <code>a</code> is null.
+ * @param v the array to represent
+ * @return a String representing this array
+ * @since 1.5
+ */
+ public static String toString(boolean[] v)
+ {
+ if (v == null)
+ return "null";
+ CPStringBuilder b = new CPStringBuilder("[");
+ for (int i = 0; i < v.length; ++i)
+ {
+ if (i > 0)
+ b.append(", ");
+ b.append(v[i]);
+ }
+ b.append("]");
+ return b.toString();
+ }
+
+ /**
+ * Returns a String representation of the argument array. Returns "null"
+ * if <code>a</code> is null.
+ * @param v the array to represent
+ * @return a String representing this array
+ * @since 1.5
+ */
+ public static String toString(byte[] v)
+ {
+ if (v == null)
+ return "null";
+ CPStringBuilder b = new CPStringBuilder("[");
+ for (int i = 0; i < v.length; ++i)
+ {
+ if (i > 0)
+ b.append(", ");
+ b.append(v[i]);
+ }
+ b.append("]");
+ return b.toString();
+ }
+
+ /**
+ * Returns a String representation of the argument array. Returns "null"
+ * if <code>a</code> is null.
+ * @param v the array to represent
+ * @return a String representing this array
+ * @since 1.5
+ */
+ public static String toString(char[] v)
+ {
+ if (v == null)
+ return "null";
+ CPStringBuilder b = new CPStringBuilder("[");
+ for (int i = 0; i < v.length; ++i)
+ {
+ if (i > 0)
+ b.append(", ");
+ b.append(v[i]);
+ }
+ b.append("]");
+ return b.toString();
+ }
+
+ /**
+ * Returns a String representation of the argument array. Returns "null"
+ * if <code>a</code> is null.
+ * @param v the array to represent
+ * @return a String representing this array
+ * @since 1.5
+ */
+ public static String toString(short[] v)
+ {
+ if (v == null)
+ return "null";
+ CPStringBuilder b = new CPStringBuilder("[");
+ for (int i = 0; i < v.length; ++i)
+ {
+ if (i > 0)
+ b.append(", ");
+ b.append(v[i]);
+ }
+ b.append("]");
+ return b.toString();
+ }
+
+ /**
+ * Returns a String representation of the argument array. Returns "null"
+ * if <code>a</code> is null.
+ * @param v the array to represent
+ * @return a String representing this array
+ * @since 1.5
+ */
+ public static String toString(int[] v)
+ {
+ if (v == null)
+ return "null";
+ CPStringBuilder b = new CPStringBuilder("[");
+ for (int i = 0; i < v.length; ++i)
+ {
+ if (i > 0)
+ b.append(", ");
+ b.append(v[i]);
+ }
+ b.append("]");
+ return b.toString();
+ }
+
+ /**
+ * Returns a String representation of the argument array. Returns "null"
+ * if <code>a</code> is null.
+ * @param v the array to represent
+ * @return a String representing this array
+ * @since 1.5
+ */
+ public static String toString(long[] v)
+ {
+ if (v == null)
+ return "null";
+ CPStringBuilder b = new CPStringBuilder("[");
+ for (int i = 0; i < v.length; ++i)
+ {
+ if (i > 0)
+ b.append(", ");
+ b.append(v[i]);
+ }
+ b.append("]");
+ return b.toString();
+ }
+
+ /**
+ * Returns a String representation of the argument array. Returns "null"
+ * if <code>a</code> is null.
+ * @param v the array to represent
+ * @return a String representing this array
+ * @since 1.5
+ */
+ public static String toString(float[] v)
+ {
+ if (v == null)
+ return "null";
+ CPStringBuilder b = new CPStringBuilder("[");
+ for (int i = 0; i < v.length; ++i)
+ {
+ if (i > 0)
+ b.append(", ");
+ b.append(v[i]);
+ }
+ b.append("]");
+ return b.toString();
+ }
+
+ /**
+ * Returns a String representation of the argument array. Returns "null"
+ * if <code>a</code> is null.
+ * @param v the array to represent
+ * @return a String representing this array
+ * @since 1.5
+ */
+ public static String toString(double[] v)
+ {
+ if (v == null)
+ return "null";
+ CPStringBuilder b = new CPStringBuilder("[");
+ for (int i = 0; i < v.length; ++i)
+ {
+ if (i > 0)
+ b.append(", ");
+ b.append(v[i]);
+ }
+ b.append("]");
+ return b.toString();
+ }
+
+ /**
+ * Returns a String representation of the argument array. Returns "null"
+ * if <code>a</code> is null.
+ * @param v the array to represent
+ * @return a String representing this array
+ * @since 1.5
+ */
+ public static String toString(Object[] v)
+ {
+ if (v == null)
+ return "null";
+ CPStringBuilder b = new CPStringBuilder("[");
+ for (int i = 0; i < v.length; ++i)
+ {
+ if (i > 0)
+ b.append(", ");
+ b.append(v[i]);
+ }
+ b.append("]");
+ return b.toString();
+ }
+
+ private static void deepToString(Object[] v, CPStringBuilder b, HashSet seen)
+ {
+ b.append("[");
+ for (int i = 0; i < v.length; ++i)
+ {
+ if (i > 0)
+ b.append(", ");
+ Object elt = v[i];
+ if (elt == null)
+ b.append("null");
+ else if (elt instanceof boolean[])
+ b.append(toString((boolean[]) elt));
+ else if (elt instanceof byte[])
+ b.append(toString((byte[]) elt));
+ else if (elt instanceof char[])
+ b.append(toString((char[]) elt));
+ else if (elt instanceof short[])
+ b.append(toString((short[]) elt));
+ else if (elt instanceof int[])
+ b.append(toString((int[]) elt));
+ else if (elt instanceof long[])
+ b.append(toString((long[]) elt));
+ else if (elt instanceof float[])
+ b.append(toString((float[]) elt));
+ else if (elt instanceof double[])
+ b.append(toString((double[]) elt));
+ else if (elt instanceof Object[])
+ {
+ Object[] os = (Object[]) elt;
+ if (seen.contains(os))
+ b.append("[...]");
+ else
+ {
+ seen.add(os);
+ deepToString(os, b, seen);
+ }
+ }
+ else
+ b.append(elt);
+ }
+ b.append("]");
+ }
+
+ /** @since 1.5 */
+ public static String deepToString(Object[] v)
+ {
+ if (v == null)
+ return "null";
+ HashSet seen = new HashSet();
+ CPStringBuilder b = new CPStringBuilder();
+ deepToString(v, b, seen);
+ return b.toString();
+ }
+
+ /**
+ * Inner class used by {@link #asList(Object[])} to provide a list interface
+ * to an array. The name, though it clashes with java.util.ArrayList, is
+ * Sun's choice for Serialization purposes. Element addition and removal
+ * is prohibited, but values can be modified.
+ *
+ * @author Eric Blake (ebb9@email.byu.edu)
+ * @status updated to 1.4
+ */
+ private static final class ArrayList<E> extends AbstractList<E>
+ implements Serializable, RandomAccess
+ {
+ // We override the necessary methods, plus others which will be much
+ // more efficient with direct iteration rather than relying on iterator().
+
+ /**
+ * Compatible with JDK 1.4.
+ */
+ private static final long serialVersionUID = -2764017481108945198L;
+
+ /**
+ * The array we are viewing.
+ * @serial the array
+ */
+ private final E[] a;
+
+ /**
+ * Construct a list view of the array.
+ * @param a the array to view
+ * @throws NullPointerException if a is null
+ */
+ ArrayList(E[] a)
+ {
+ // We have to explicitly check.
+ if (a == null)
+ throw new NullPointerException();
+ this.a = a;
+ }
+
+ /**
+ * Returns the object at the specified index in
+ * the array.
+ *
+ * @param index The index to retrieve an object from.
+ * @return The object at the array index specified.
+ */
+ public E get(int index)
+ {
+ return a[index];
+ }
+
+ /**
+ * Returns the size of the array.
+ *
+ * @return The size.
+ */
+ public int size()
+ {
+ return a.length;
+ }
+
+ /**
+ * Replaces the object at the specified index
+ * with the supplied element.
+ *
+ * @param index The index at which to place the new object.
+ * @param element The new object.
+ * @return The object replaced by this operation.
+ */
+ public E set(int index, E element)
+ {
+ E old = a[index];
+ a[index] = element;
+ return old;
+ }
+
+ /**
+ * Returns true if the array contains the
+ * supplied object.
+ *
+ * @param o The object to look for.
+ * @return True if the object was found.
+ */
+ public boolean contains(Object o)
+ {
+ return lastIndexOf(o) >= 0;
+ }
+
+ /**
+ * Returns the first index at which the
+ * object, o, occurs in the array.
+ *
+ * @param o The object to search for.
+ * @return The first relevant index.
+ */
+ public int indexOf(Object o)
+ {
+ int size = a.length;
+ for (int i = 0; i < size; i++)
+ if (ArrayList.equals(o, a[i]))
+ return i;
+ return -1;
+ }
+
+ /**
+ * Returns the last index at which the
+ * object, o, occurs in the array.
+ *
+ * @param o The object to search for.
+ * @return The last relevant index.
+ */
+ public int lastIndexOf(Object o)
+ {
+ int i = a.length;
+ while (--i >= 0)
+ if (ArrayList.equals(o, a[i]))
+ return i;
+ return -1;
+ }
+
+ /**
+ * Transforms the list into an array of
+ * objects, by simplying cloning the array
+ * wrapped by this list.
+ *
+ * @return A clone of the internal array.
+ */
+ public Object[] toArray()
+ {
+ return (Object[]) a.clone();
+ }
+
+ /**
+ * Copies the objects from this list into
+ * the supplied array. The supplied array
+ * is shrunk or enlarged to the size of the
+ * internal array, and filled with its objects.
+ *
+ * @param array The array to fill with the objects in this list.
+ * @return The array containing the objects in this list,
+ * which may or may not be == to array.
+ */
+ public <T> T[] toArray(T[] array)
+ {
+ int size = a.length;
+ if (array.length < size)
+ array = (T[]) Array.newInstance(array.getClass().getComponentType(),
+ size);
+ else if (array.length > size)
+ array[size] = null;
+
+ System.arraycopy(a, 0, array, 0, size);
+ return array;
+ }
+ }
+
+ /**
+ * Returns a copy of the supplied array, truncating or padding as
+ * necessary with <code>false</code> to obtain the specified length.
+ * Indices that are valid for both arrays will return the same value.
+ * Indices that only exist in the returned array (due to the new length
+ * being greater than the original length) will return <code>false</code>.
+ * This is equivalent to calling
+ * <code>copyOfRange(original, 0, newLength)</code>.
+ *
+ * @param original the original array to be copied.
+ * @param newLength the length of the returned array.
+ * @return a copy of the original array, truncated or padded with
+ * <code>false</code> to obtain the required length.
+ * @throws NegativeArraySizeException if <code>newLength</code> is negative.
+ * @throws NullPointerException if <code>original</code> is <code>null</code>.
+ * @since 1.6
+ * @see #copyOfRange(boolean[],int,int)
+ */
+ public static boolean[] copyOf(boolean[] original, int newLength)
+ {
+ if (newLength < 0)
+ throw new NegativeArraySizeException("The array size is negative.");
+ return copyOfRange(original, 0, newLength);
+ }
+
+ /**
+ * Copies the specified range of the supplied array to a new
+ * array, padding as necessary with <code>false</code>
+ * if <code>to</code> is greater than the length of the original
+ * array. <code>from</code> must be in the range zero to
+ * <code>original.length</code> and can not be greater than
+ * <code>to</code>. The initial element of the
+ * returned array will be equal to <code>original[from]</code>,
+ * except where <code>from</code> is equal to <code>to</code>
+ * (where a zero-length array will be returned) or <code>
+ * <code>from</code> is equal to <code>original.length</code>
+ * (where an array padded with <code>false</code> will be
+ * returned). The returned array is always of length
+ * <code>to - from</code>.
+ *
+ * @param original the array from which to copy.
+ * @param from the initial index of the range, inclusive.
+ * @param to the final index of the range, exclusive.
+ * @return a copy of the specified range, with padding to
+ * obtain the required length.
+ * @throws ArrayIndexOutOfBoundsException if <code>from < 0</code>
+ * or <code>from > original.length</code>
+ * @throws IllegalArgumentException if <code>from > to</code>
+ * @throws NullPointerException if <code>original</code> is <code>null</code>.
+ * @since 1.6
+ * @see #copyOf(boolean[],int)
+ */
+ public static boolean[] copyOfRange(boolean[] original, int from, int to)
+ {
+ if (from > to)
+ throw new IllegalArgumentException("The initial index is after " +
+ "the final index.");
+ boolean[] newArray = new boolean[to - from];
+ if (to > original.length)
+ {
+ System.arraycopy(original, from, newArray, 0,
+ original.length - from);
+ fill(newArray, original.length, newArray.length, false);
+ }
+ else
+ System.arraycopy(original, from, newArray, 0, to - from);
+ return newArray;
+ }
+
+ /**
+ * Returns a copy of the supplied array, truncating or padding as
+ * necessary with <code>(byte)0</code> to obtain the specified length.
+ * Indices that are valid for both arrays will return the same value.
+ * Indices that only exist in the returned array (due to the new length
+ * being greater than the original length) will return <code>(byte)0</code>.
+ * This is equivalent to calling
+ * <code>copyOfRange(original, 0, newLength)</code>.
+ *
+ * @param original the original array to be copied.
+ * @param newLength the length of the returned array.
+ * @return a copy of the original array, truncated or padded with
+ * <code>(byte)0</code> to obtain the required length.
+ * @throws NegativeArraySizeException if <code>newLength</code> is negative.
+ * @throws NullPointerException if <code>original</code> is <code>null</code>.
+ * @since 1.6
+ * @see #copyOfRange(byte[],int,int)
+ */
+ public static byte[] copyOf(byte[] original, int newLength)
+ {
+ if (newLength < 0)
+ throw new NegativeArraySizeException("The array size is negative.");
+ return copyOfRange(original, 0, newLength);
+ }
+
+ /**
+ * Copies the specified range of the supplied array to a new
+ * array, padding as necessary with <code>(byte)0</code>
+ * if <code>to</code> is greater than the length of the original
+ * array. <code>from</code> must be in the range zero to
+ * <code>original.length</code> and can not be greater than
+ * <code>to</code>. The initial element of the
+ * returned array will be equal to <code>original[from]</code>,
+ * except where <code>from</code> is equal to <code>to</code>
+ * (where a zero-length array will be returned) or <code>
+ * <code>from</code> is equal to <code>original.length</code>
+ * (where an array padded with <code>(byte)0</code> will be
+ * returned). The returned array is always of length
+ * <code>to - from</code>.
+ *
+ * @param original the array from which to copy.
+ * @param from the initial index of the range, inclusive.
+ * @param to the final index of the range, exclusive.
+ * @return a copy of the specified range, with padding to
+ * obtain the required length.
+ * @throws ArrayIndexOutOfBoundsException if <code>from < 0</code>
+ * or <code>from > original.length</code>
+ * @throws IllegalArgumentException if <code>from > to</code>
+ * @throws NullPointerException if <code>original</code> is <code>null</code>.
+ * @since 1.6
+ * @see #copyOf(byte[],int)
+ */
+ public static byte[] copyOfRange(byte[] original, int from, int to)
+ {
+ if (from > to)
+ throw new IllegalArgumentException("The initial index is after " +
+ "the final index.");
+ byte[] newArray = new byte[to - from];
+ if (to > original.length)
+ {
+ System.arraycopy(original, from, newArray, 0,
+ original.length - from);
+ fill(newArray, original.length, newArray.length, (byte)0);
+ }
+ else
+ System.arraycopy(original, from, newArray, 0, to - from);
+ return newArray;
+ }
+
+ /**
+ * Returns a copy of the supplied array, truncating or padding as
+ * necessary with <code>'\0'</code> to obtain the specified length.
+ * Indices that are valid for both arrays will return the same value.
+ * Indices that only exist in the returned array (due to the new length
+ * being greater than the original length) will return <code>'\0'</code>.
+ * This is equivalent to calling
+ * <code>copyOfRange(original, 0, newLength)</code>.
+ *
+ * @param original the original array to be copied.
+ * @param newLength the length of the returned array.
+ * @return a copy of the original array, truncated or padded with
+ * <code>'\0'</code> to obtain the required length.
+ * @throws NegativeArraySizeException if <code>newLength</code> is negative.
+ * @throws NullPointerException if <code>original</code> is <code>null</code>.
+ * @since 1.6
+ * @see #copyOfRange(char[],int,int)
+ */
+ public static char[] copyOf(char[] original, int newLength)
+ {
+ if (newLength < 0)
+ throw new NegativeArraySizeException("The array size is negative.");
+ return copyOfRange(original, 0, newLength);
+ }
+
+ /**
+ * Copies the specified range of the supplied array to a new
+ * array, padding as necessary with <code>'\0'</code>
+ * if <code>to</code> is greater than the length of the original
+ * array. <code>from</code> must be in the range zero to
+ * <code>original.length</code> and can not be greater than
+ * <code>to</code>. The initial element of the
+ * returned array will be equal to <code>original[from]</code>,
+ * except where <code>from</code> is equal to <code>to</code>
+ * (where a zero-length array will be returned) or <code>
+ * <code>from</code> is equal to <code>original.length</code>
+ * (where an array padded with <code>'\0'</code> will be
+ * returned). The returned array is always of length
+ * <code>to - from</code>.
+ *
+ * @param original the array from which to copy.
+ * @param from the initial index of the range, inclusive.
+ * @param to the final index of the range, exclusive.
+ * @return a copy of the specified range, with padding to
+ * obtain the required length.
+ * @throws ArrayIndexOutOfBoundsException if <code>from < 0</code>
+ * or <code>from > original.length</code>
+ * @throws IllegalArgumentException if <code>from > to</code>
+ * @throws NullPointerException if <code>original</code> is <code>null</code>.
+ * @since 1.6
+ * @see #copyOf(char[],int)
+ */
+ public static char[] copyOfRange(char[] original, int from, int to)
+ {
+ if (from > to)
+ throw new IllegalArgumentException("The initial index is after " +
+ "the final index.");
+ char[] newArray = new char[to - from];
+ if (to > original.length)
+ {
+ System.arraycopy(original, from, newArray, 0,
+ original.length - from);
+ fill(newArray, original.length, newArray.length, '\0');
+ }
+ else
+ System.arraycopy(original, from, newArray, 0, to - from);
+ return newArray;
+ }
+
+ /**
+ * Returns a copy of the supplied array, truncating or padding as
+ * necessary with <code>0d</code> to obtain the specified length.
+ * Indices that are valid for both arrays will return the same value.
+ * Indices that only exist in the returned array (due to the new length
+ * being greater than the original length) will return <code>0d</code>.
+ * This is equivalent to calling
+ * <code>copyOfRange(original, 0, newLength)</code>.
+ *
+ * @param original the original array to be copied.
+ * @param newLength the length of the returned array.
+ * @return a copy of the original array, truncated or padded with
+ * <code>0d</code> to obtain the required length.
+ * @throws NegativeArraySizeException if <code>newLength</code> is negative.
+ * @throws NullPointerException if <code>original</code> is <code>null</code>.
+ * @since 1.6
+ * @see #copyOfRange(double[],int,int)
+ */
+ public static double[] copyOf(double[] original, int newLength)
+ {
+ if (newLength < 0)
+ throw new NegativeArraySizeException("The array size is negative.");
+ return copyOfRange(original, 0, newLength);
+ }
+
+ /**
+ * Copies the specified range of the supplied array to a new
+ * array, padding as necessary with <code>0d</code>
+ * if <code>to</code> is greater than the length of the original
+ * array. <code>from</code> must be in the range zero to
+ * <code>original.length</code> and can not be greater than
+ * <code>to</code>. The initial element of the
+ * returned array will be equal to <code>original[from]</code>,
+ * except where <code>from</code> is equal to <code>to</code>
+ * (where a zero-length array will be returned) or <code>
+ * <code>from</code> is equal to <code>original.length</code>
+ * (where an array padded with <code>0d</code> will be
+ * returned). The returned array is always of length
+ * <code>to - from</code>.
+ *
+ * @param original the array from which to copy.
+ * @param from the initial index of the range, inclusive.
+ * @param to the final index of the range, exclusive.
+ * @return a copy of the specified range, with padding to
+ * obtain the required length.
+ * @throws ArrayIndexOutOfBoundsException if <code>from < 0</code>
+ * or <code>from > original.length</code>
+ * @throws IllegalArgumentException if <code>from > to</code>
+ * @throws NullPointerException if <code>original</code> is <code>null</code>.
+ * @since 1.6
+ * @see #copyOf(double[],int)
+ */
+ public static double[] copyOfRange(double[] original, int from, int to)
+ {
+ if (from > to)
+ throw new IllegalArgumentException("The initial index is after " +
+ "the final index.");
+ double[] newArray = new double[to - from];
+ if (to > original.length)
+ {
+ System.arraycopy(original, from, newArray, 0,
+ original.length - from);
+ fill(newArray, original.length, newArray.length, 0d);
+ }
+ else
+ System.arraycopy(original, from, newArray, 0, to - from);
+ return newArray;
+ }
+
+ /**
+ * Returns a copy of the supplied array, truncating or padding as
+ * necessary with <code>0f</code> to obtain the specified length.
+ * Indices that are valid for both arrays will return the same value.
+ * Indices that only exist in the returned array (due to the new length
+ * being greater than the original length) will return <code>0f</code>.
+ * This is equivalent to calling
+ * <code>copyOfRange(original, 0, newLength)</code>.
+ *
+ * @param original the original array to be copied.
+ * @param newLength the length of the returned array.
+ * @return a copy of the original array, truncated or padded with
+ * <code>0f</code> to obtain the required length.
+ * @throws NegativeArraySizeException if <code>newLength</code> is negative.
+ * @throws NullPointerException if <code>original</code> is <code>null</code>.
+ * @since 1.6
+ * @see #copyOfRange(float[],int,int)
+ */
+ public static float[] copyOf(float[] original, int newLength)
+ {
+ if (newLength < 0)
+ throw new NegativeArraySizeException("The array size is negative.");
+ return copyOfRange(original, 0, newLength);
+ }
+
+ /**
+ * Copies the specified range of the supplied array to a new
+ * array, padding as necessary with <code>0f</code>
+ * if <code>to</code> is greater than the length of the original
+ * array. <code>from</code> must be in the range zero to
+ * <code>original.length</code> and can not be greater than
+ * <code>to</code>. The initial element of the
+ * returned array will be equal to <code>original[from]</code>,
+ * except where <code>from</code> is equal to <code>to</code>
+ * (where a zero-length array will be returned) or <code>
+ * <code>from</code> is equal to <code>original.length</code>
+ * (where an array padded with <code>0f</code> will be
+ * returned). The returned array is always of length
+ * <code>to - from</code>.
+ *
+ * @param original the array from which to copy.
+ * @param from the initial index of the range, inclusive.
+ * @param to the final index of the range, exclusive.
+ * @return a copy of the specified range, with padding to
+ * obtain the required length.
+ * @throws ArrayIndexOutOfBoundsException if <code>from < 0</code>
+ * or <code>from > original.length</code>
+ * @throws IllegalArgumentException if <code>from > to</code>
+ * @throws NullPointerException if <code>original</code> is <code>null</code>.
+ * @since 1.6
+ * @see #copyOf(float[],int)
+ */
+ public static float[] copyOfRange(float[] original, int from, int to)
+ {
+ if (from > to)
+ throw new IllegalArgumentException("The initial index is after " +
+ "the final index.");
+ float[] newArray = new float[to - from];
+ if (to > original.length)
+ {
+ System.arraycopy(original, from, newArray, 0,
+ original.length - from);
+ fill(newArray, original.length, newArray.length, 0f);
+ }
+ else
+ System.arraycopy(original, from, newArray, 0, to - from);
+ return newArray;
+ }
+
+ /**
+ * Returns a copy of the supplied array, truncating or padding as
+ * necessary with <code>0</code> to obtain the specified length.
+ * Indices that are valid for both arrays will return the same value.
+ * Indices that only exist in the returned array (due to the new length
+ * being greater than the original length) will return <code>0</code>.
+ * This is equivalent to calling
+ * <code>copyOfRange(original, 0, newLength)</code>.
+ *
+ * @param original the original array to be copied.
+ * @param newLength the length of the returned array.
+ * @return a copy of the original array, truncated or padded with
+ * <code>0</code> to obtain the required length.
+ * @throws NegativeArraySizeException if <code>newLength</code> is negative.
+ * @throws NullPointerException if <code>original</code> is <code>null</code>.
+ * @since 1.6
+ * @see #copyOfRange(int[],int,int)
+ */
+ public static int[] copyOf(int[] original, int newLength)
+ {
+ if (newLength < 0)
+ throw new NegativeArraySizeException("The array size is negative.");
+ return copyOfRange(original, 0, newLength);
+ }
+
+ /**
+ * Copies the specified range of the supplied array to a new
+ * array, padding as necessary with <code>0</code>
+ * if <code>to</code> is greater than the length of the original
+ * array. <code>from</code> must be in the range zero to
+ * <code>original.length</code> and can not be greater than
+ * <code>to</code>. The initial element of the
+ * returned array will be equal to <code>original[from]</code>,
+ * except where <code>from</code> is equal to <code>to</code>
+ * (where a zero-length array will be returned) or <code>
+ * <code>from</code> is equal to <code>original.length</code>
+ * (where an array padded with <code>0</code> will be
+ * returned). The returned array is always of length
+ * <code>to - from</code>.
+ *
+ * @param original the array from which to copy.
+ * @param from the initial index of the range, inclusive.
+ * @param to the final index of the range, exclusive.
+ * @return a copy of the specified range, with padding to
+ * obtain the required length.
+ * @throws ArrayIndexOutOfBoundsException if <code>from < 0</code>
+ * or <code>from > original.length</code>
+ * @throws IllegalArgumentException if <code>from > to</code>
+ * @throws NullPointerException if <code>original</code> is <code>null</code>.
+ * @since 1.6
+ * @see #copyOf(int[],int)
+ */
+ public static int[] copyOfRange(int[] original, int from, int to)
+ {
+ if (from > to)
+ throw new IllegalArgumentException("The initial index is after " +
+ "the final index.");
+ int[] newArray = new int[to - from];
+ if (to > original.length)
+ {
+ System.arraycopy(original, from, newArray, 0,
+ original.length - from);
+ fill(newArray, original.length, newArray.length, 0);
+ }
+ else
+ System.arraycopy(original, from, newArray, 0, to - from);
+ return newArray;
+ }
+
+ /**
+ * Returns a copy of the supplied array, truncating or padding as
+ * necessary with <code>0L</code> to obtain the specified length.
+ * Indices that are valid for both arrays will return the same value.
+ * Indices that only exist in the returned array (due to the new length
+ * being greater than the original length) will return <code>0L</code>.
+ * This is equivalent to calling
+ * <code>copyOfRange(original, 0, newLength)</code>.
+ *
+ * @param original the original array to be copied.
+ * @param newLength the length of the returned array.
+ * @return a copy of the original array, truncated or padded with
+ * <code>0L</code> to obtain the required length.
+ * @throws NegativeArraySizeException if <code>newLength</code> is negative.
+ * @throws NullPointerException if <code>original</code> is <code>null</code>.
+ * @since 1.6
+ * @see #copyOfRange(long[],int,int)
+ */
+ public static long[] copyOf(long[] original, int newLength)
+ {
+ if (newLength < 0)
+ throw new NegativeArraySizeException("The array size is negative.");
+ return copyOfRange(original, 0, newLength);
+ }
+
+ /**
+ * Copies the specified range of the supplied array to a new
+ * array, padding as necessary with <code>0L</code>
+ * if <code>to</code> is greater than the length of the original
+ * array. <code>from</code> must be in the range zero to
+ * <code>original.length</code> and can not be greater than
+ * <code>to</code>. The initial element of the
+ * returned array will be equal to <code>original[from]</code>,
+ * except where <code>from</code> is equal to <code>to</code>
+ * (where a zero-length array will be returned) or <code>
+ * <code>from</code> is equal to <code>original.length</code>
+ * (where an array padded with <code>0L</code> will be
+ * returned). The returned array is always of length
+ * <code>to - from</code>.
+ *
+ * @param original the array from which to copy.
+ * @param from the initial index of the range, inclusive.
+ * @param to the final index of the range, exclusive.
+ * @return a copy of the specified range, with padding to
+ * obtain the required length.
+ * @throws ArrayIndexOutOfBoundsException if <code>from < 0</code>
+ * or <code>from > original.length</code>
+ * @throws IllegalArgumentException if <code>from > to</code>
+ * @throws NullPointerException if <code>original</code> is <code>null</code>.
+ * @since 1.6
+ * @see #copyOf(long[],int)
+ */
+ public static long[] copyOfRange(long[] original, int from, int to)
+ {
+ if (from > to)
+ throw new IllegalArgumentException("The initial index is after " +
+ "the final index.");
+ long[] newArray = new long[to - from];
+ if (to > original.length)
+ {
+ System.arraycopy(original, from, newArray, 0,
+ original.length - from);
+ fill(newArray, original.length, newArray.length, 0L);
+ }
+ else
+ System.arraycopy(original, from, newArray, 0, to - from);
+ return newArray;
+ }
+
+ /**
+ * Returns a copy of the supplied array, truncating or padding as
+ * necessary with <code>(short)0</code> to obtain the specified length.
+ * Indices that are valid for both arrays will return the same value.
+ * Indices that only exist in the returned array (due to the new length
+ * being greater than the original length) will return <code>(short)0</code>.
+ * This is equivalent to calling
+ * <code>copyOfRange(original, 0, newLength)</code>.
+ *
+ * @param original the original array to be copied.
+ * @param newLength the length of the returned array.
+ * @return a copy of the original array, truncated or padded with
+ * <code>(short)0</code> to obtain the required length.
+ * @throws NegativeArraySizeException if <code>newLength</code> is negative.
+ * @throws NullPointerException if <code>original</code> is <code>null</code>.
+ * @since 1.6
+ * @see #copyOfRange(short[],int,int)
+ */
+ public static short[] copyOf(short[] original, int newLength)
+ {
+ if (newLength < 0)
+ throw new NegativeArraySizeException("The array size is negative.");
+ return copyOfRange(original, 0, newLength);
+ }
+
+ /**
+ * Copies the specified range of the supplied array to a new
+ * array, padding as necessary with <code>(short)0</code>
+ * if <code>to</code> is greater than the length of the original
+ * array. <code>from</code> must be in the range zero to
+ * <code>original.length</code> and can not be greater than
+ * <code>to</code>. The initial element of the
+ * returned array will be equal to <code>original[from]</code>,
+ * except where <code>from</code> is equal to <code>to</code>
+ * (where a zero-length array will be returned) or <code>
+ * <code>from</code> is equal to <code>original.length</code>
+ * (where an array padded with <code>(short)0</code> will be
+ * returned). The returned array is always of length
+ * <code>to - from</code>.
+ *
+ * @param original the array from which to copy.
+ * @param from the initial index of the range, inclusive.
+ * @param to the final index of the range, exclusive.
+ * @return a copy of the specified range, with padding to
+ * obtain the required length.
+ * @throws ArrayIndexOutOfBoundsException if <code>from < 0</code>
+ * or <code>from > original.length</code>
+ * @throws IllegalArgumentException if <code>from > to</code>
+ * @throws NullPointerException if <code>original</code> is <code>null</code>.
+ * @since 1.6
+ * @see #copyOf(short[],int)
+ */
+ public static short[] copyOfRange(short[] original, int from, int to)
+ {
+ if (from > to)
+ throw new IllegalArgumentException("The initial index is after " +
+ "the final index.");
+ short[] newArray = new short[to - from];
+ if (to > original.length)
+ {
+ System.arraycopy(original, from, newArray, 0,
+ original.length - from);
+ fill(newArray, original.length, newArray.length, (short)0);
+ }
+ else
+ System.arraycopy(original, from, newArray, 0, to - from);
+ return newArray;
+ }
+
+ /**
+ * Returns a copy of the supplied array, truncating or padding as
+ * necessary with <code>null</code> to obtain the specified length.
+ * Indices that are valid for both arrays will return the same value.
+ * Indices that only exist in the returned array (due to the new length
+ * being greater than the original length) will return <code>null</code>.
+ * This is equivalent to calling
+ * <code>copyOfRange(original, 0, newLength)</code>.
+ *
+ * @param original the original array to be copied.
+ * @param newLength the length of the returned array.
+ * @return a copy of the original array, truncated or padded with
+ * <code>null</code> to obtain the required length.
+ * @throws NegativeArraySizeException if <code>newLength</code> is negative.
+ * @throws NullPointerException if <code>original</code> is <code>null</code>.
+ * @since 1.6
+ * @see #copyOfRange(T[],int,int)
+ */
+ public static <T> T[] copyOf(T[] original, int newLength)
+ {
+ if (newLength < 0)
+ throw new NegativeArraySizeException("The array size is negative.");
+ return copyOfRange(original, 0, newLength);
+ }
+
+ /**
+ * Copies the specified range of the supplied array to a new
+ * array, padding as necessary with <code>null</code>
+ * if <code>to</code> is greater than the length of the original
+ * array. <code>from</code> must be in the range zero to
+ * <code>original.length</code> and can not be greater than
+ * <code>to</code>. The initial element of the
+ * returned array will be equal to <code>original[from]</code>,
+ * except where <code>from</code> is equal to <code>to</code>
+ * (where a zero-length array will be returned) or <code>
+ * <code>from</code> is equal to <code>original.length</code>
+ * (where an array padded with <code>null</code> will be
+ * returned). The returned array is always of length
+ * <code>to - from</code>.
+ *
+ * @param original the array from which to copy.
+ * @param from the initial index of the range, inclusive.
+ * @param to the final index of the range, exclusive.
+ * @return a copy of the specified range, with padding to
+ * obtain the required length.
+ * @throws ArrayIndexOutOfBoundsException if <code>from < 0</code>
+ * or <code>from > original.length</code>
+ * @throws IllegalArgumentException if <code>from > to</code>
+ * @throws NullPointerException if <code>original</code> is <code>null</code>.
+ * @since 1.6
+ * @see #copyOf(T[],int)
+ */
+ public static <T> T[] copyOfRange(T[] original, int from, int to)
+ {
+ if (from > to)
+ throw new IllegalArgumentException("The initial index is after " +
+ "the final index.");
+ Class elemType = original.getClass().getComponentType();
+ T[] newArray = (T[]) Array.newInstance(elemType, to - from);
+ if (to > original.length)
+ {
+ System.arraycopy(original, from, newArray, 0,
+ original.length - from);
+ fill(newArray, original.length, newArray.length, null);
+ }
+ else
+ System.arraycopy(original, from, newArray, 0, to - from);
+ return newArray;
+ }
+
+ /**
+ * Returns a copy of the supplied array, truncating or padding as
+ * necessary with <code>null</code> to obtain the specified length.
+ * Indices that are valid for both arrays will return the same value.
+ * Indices that only exist in the returned array (due to the new length
+ * being greater than the original length) will return <code>null</code>.
+ * This is equivalent to calling
+ * <code>copyOfRange(original, 0, newLength, newType)</code>. The returned
+ * array will be of the specified type, <code>newType</code>.
+ *
+ * @param original the original array to be copied.
+ * @param newLength the length of the returned array.
+ * @param newType the type of the returned array.
+ * @return a copy of the original array, truncated or padded with
+ * <code>null</code> to obtain the required length.
+ * @throws NegativeArraySizeException if <code>newLength</code> is negative.
+ * @throws NullPointerException if <code>original</code> is <code>null</code>.
+ * @since 1.6
+ * @see #copyOfRange(U[],int,int,Class)
+ */
+ public static <T,U> T[] copyOf(U[] original, int newLength,
+ Class<? extends T[]> newType)
+ {
+ if (newLength < 0)
+ throw new NegativeArraySizeException("The array size is negative.");
+ return copyOfRange(original, 0, newLength, newType);
+ }
+
+ /**
+ * Copies the specified range of the supplied array to a new
+ * array, padding as necessary with <code>null</code>
+ * if <code>to</code> is greater than the length of the original
+ * array. <code>from</code> must be in the range zero to
+ * <code>original.length</code> and can not be greater than
+ * <code>to</code>. The initial element of the
+ * returned array will be equal to <code>original[from]</code>,
+ * except where <code>from</code> is equal to <code>to</code>
+ * (where a zero-length array will be returned) or <code>
+ * <code>from</code> is equal to <code>original.length</code>
+ * (where an array padded with <code>null</code> will be
+ * returned). The returned array is always of length
+ * <code>to - from</code> and will be of the specified type,
+ * <code>newType</code>.
+ *
+ * @param original the array from which to copy.
+ * @param from the initial index of the range, inclusive.
+ * @param to the final index of the range, exclusive.
+ * @param newType the type of the returned array.
+ * @return a copy of the specified range, with padding to
+ * obtain the required length.
+ * @throws ArrayIndexOutOfBoundsException if <code>from < 0</code>
+ * or <code>from > original.length</code>
+ * @throws IllegalArgumentException if <code>from > to</code>
+ * @throws NullPointerException if <code>original</code> is <code>null</code>.
+ * @since 1.6
+ * @see #copyOf(T[],int)
+ */
+ public static <T,U> T[] copyOfRange(U[] original, int from, int to,
+ Class<? extends T[]> newType)
+ {
+ if (from > to)
+ throw new IllegalArgumentException("The initial index is after " +
+ "the final index.");
+ T[] newArray = (T[]) Array.newInstance(newType.getComponentType(),
+ to - from);
+ if (to > original.length)
+ {
+ System.arraycopy(original, from, newArray, 0,
+ original.length - from);
+ fill(newArray, original.length, newArray.length, null);
+ }
+ else
+ System.arraycopy(original, from, newArray, 0, to - from);
+ return newArray;
+ }
+}
projects / IRC.git / commitdiff