--- /dev/null
+
+
+public class ArrayList
+{
+ /**
+ * The array buffer into which the elements of the ArrayList are stored.
+ * The capacity of the ArrayList is the length of this array buffer.
+ */
+ private Object[] elementData;
+ private int size;
+
+ public ArrayList(int initialCapacity) {
+ this.elementData = new Object[initialCapacity];
+ }
+
+ public ArrayList() {
+ this.elementData = new Object[10];
+ }
+
+ /**
+ * Returns the number of elements in this list.
+ *
+ * @return the number of elements in this list
+ */
+ public int size() {
+ return size;
+ }
+
+ /**
+ * Returns <tt>true</tt> if this list contains no elements.
+ *
+ * @return <tt>true</tt> if this list contains no elements
+ */
+ public boolean isEmpty() {
+ return size == 0;
+ }
+
+ /**
+ * Returns <tt>true</tt> if this list contains the specified element.
+ * More formally, returns <tt>true</tt> if and only if this list contains
+ * at least one element <tt>e</tt> such that
+ * <tt>(o==null ? e==null : o.equals(e))</tt>.
+ *
+ * @param o element whose presence in this list is to be tested
+ * @return <tt>true</tt> if this list contains the specified element
+ */
+ public boolean contains(Object o) {
+ return indexOf(o) >= 0;
+ }
+
+ /**
+ * Returns the index of the first occurrence of the specified element
+ * in this list, or -1 if this list does not contain the element.
+ * More formally, returns the lowest index <tt>i</tt> such that
+ * <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>,
+ * or -1 if there is no such index.
+ */
+ public int indexOf(Object o) {
+ if (o == null) {
+ for (int i = 0; i < size; i++)
+ if (elementData[i]==null)
+ return i;
+ } else {
+ for (int i = 0; i < size; i++)
+ if (o.equals(elementData[i]))
+ return i;
+ }
+ return -1;
+ }
+
+ /**
+ * Returns the index of the last occurrence of the specified element
+ * in this list, or -1 if this list does not contain the element.
+ * More formally, returns the highest index <tt>i</tt> such that
+ * <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>,
+ * or -1 if there is no such index.
+ */
+ public int lastIndexOf(Object o) {
+ if (o == null) {
+ for (int i = size-1; i >= 0; i--)
+ if (elementData[i]==null)
+ return i;
+ } else {
+ for (int i = size-1; i >= 0; i--)
+ if (o.equals(elementData[i]))
+ return i;
+ }
+ return -1;
+ }
+
+ /**
+ * Returns the element at the specified position in this list.
+ *
+ * @param index index of the element to return
+ * @return the element at the specified position in this list
+ * @throws NOTHING
+ */
+ public Object get(int index) {
+ RangeCheck(index);
+
+ return elementData[index];
+ }
+
+ /**
+ * Replaces the element at the specified position in this list with
+ * the specified element.
+ *
+ * @param index index of the element to replace
+ * @param element element to be stored at the specified position
+ * @return the element previously at the specified position
+ * @throws NOTHING
+ */
+ public Object set(int index, Object element) {
+ RangeCheck(index);
+
+ Object oldValue = elementData[index];
+ elementData[index] = element;
+ return oldValue;
+ }
+
+ /**
+ * Appends the specified element to the end of this list.
+ *
+ * @param e element to be appended to this list
+ * @return <tt>true</tt> (as specified by {@link Collection#add})
+ */
+ public boolean add(Object e) {
+ ensureCapacity(size + 1); // Increments modCount!!
+ elementData[size++] = e;
+ return true;
+ }
+
+ public void ensureCapacity(int minCapacity)
+ {
+ int oldCapacity = elementData.length;
+ if (minCapacity > oldCapacity)
+ {
+ Object oldData[] = elementData;
+ int newCapacity = (oldCapacity * 3)/2 + 1;
+ if (newCapacity < minCapacity)
+ newCapacity = minCapacity;
+
+ // minCapacity is usually close to size, so this is a win:
+ elementData = copyOf(elementData, newCapacity);
+ }
+ }
+
+ public Object[] copyOf(Object[] data, int newCap)
+ {
+ Object[] array = new Object[newCap];
+
+ for(int i = 0; i < size; i++)
+ array[i] = data[i];
+
+ return array;
+ }
+
+ /**
+ * Inserts the specified element at the specified position in this
+ * list. Shifts the element currently at that position (if any) and
+ * any subsequent elements to the right (adds one to their indices).
+ *
+ * @param index index at which the specified element is to be inserted
+ * @param element element to be inserted
+ * @throws NOTHING
+ */
+ public void add(int index, Object element) {
+
+ ensureCapacity(size+1); // Increments modCount!!
+ systemArrayCopy(elementData, index, elementData, index + 1,
+ size - index);
+ elementData[index] = element;
+ size++;
+ }
+
+ //Mimics System.arraycopy
+ public void systemArrayCopy(Object[] a, int orgStart, Object[] b, int newStart, int length)
+ {
+ Object[] original;
+
+ if(a != b)
+ original = a;
+ else
+ {
+ original = new Object[a.length];
+
+ for(int i = 0; i < a.length; i++)
+ original[i] = a[i];
+ }
+
+ for(int i = 0; i < length && i < (a.length - orgStart - 1) && i < (b.length - newStart - 1); i++)
+ {
+ b[i + newStart] = original[i + orgStart];
+ }
+ }
+
+
+ /**
+ * Removes the element at the specified position in this list.
+ * Shifts any subsequent elements to the left (subtracts one from their
+ * indices).
+ *
+ * @param index the index of the element to be removed
+ * @return the element that was removed from the list
+ * @throws NOTHING
+ */
+ public Object remove(int index) {
+ RangeCheck(index);
+
+
+ Object oldValue = elementData[index];
+
+ int numMoved = size - index - 1;
+ if (numMoved > 0)
+ systemArrayCopy(elementData, index+1, elementData, index,
+ numMoved);
+ elementData[--size] = null; // Let gc do its work
+
+ return oldValue;
+ }
+
+ /**
+ * Removes the first occurrence of the specified element from this list,
+ * if it is present. If the list does not contain the element, it is
+ * unchanged. More formally, removes the element with the lowest index
+ * <tt>i</tt> such that
+ * <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>
+ * (if such an element exists). Returns <tt>true</tt> if this list
+ * contained the specified element (or equivalently, if this list
+ * changed as a result of the call).
+ *
+ * @param o element to be removed from this list, if present
+ * @return <tt>true</tt> if this list contained the specified element
+ */
+ public boolean remove(Object o) {
+ if (o == null) {
+ for (int index = 0; index < size; index++)
+ if (elementData[index] == null) {
+ fastRemove(index);
+ return true;
+ }
+ } else {
+ for (int index = 0; index < size; index++)
+ if (o.equals(elementData[index])) {
+ fastRemove(index);
+ return true;
+ }
+ }
+ return false;
+ }
+
+ /*
+ * Private remove method that skips bounds checking and does not
+ * return the value removed.
+ */
+ private void fastRemove(int index)
+ {
+ int numMoved = size - index - 1;
+ if (numMoved > 0)
+ systemArrayCopy(elementData, index+1, elementData, index,
+ numMoved);
+ elementData[--size] = null; // Let gc do its work
+ }
+
+ /**
+ * Removes all of the elements from this list. The list will
+ * be empty after this call returns.
+ */
+ public void clear() {
+
+ // Let gc do its work
+ for (int i = 0; i < size; i++)
+ elementData[i] = null;
+
+ size = 0;
+ }
+
+
+
+
+ /**
+ * Removes from this list all of the elements whose index is between
+ * <tt>fromIndex</tt>, inclusive, and <tt>toIndex</tt>, exclusive.
+ * Shifts any succeeding elements to the left (reduces their index).
+ * This call shortens the list by <tt>(toIndex - fromIndex)</tt> elements.
+ * (If <tt>toIndex==fromIndex</tt>, this operation has no effect.)
+ *
+ * @param fromIndex index of first element to be removed
+ * @param toIndex index after last element to be removed
+ * @throws NOTHING
+ */
+ protected void removeRange(int fromIndex, int toIndex) {
+ int numMoved = size - toIndex;
+ systemArrayCopy(elementData, toIndex, elementData, fromIndex,
+ numMoved);
+
+ // Let gc do its work
+ int newSize = size - (toIndex-fromIndex);
+ while (size != newSize)
+ elementData[--size] = null;
+ }
+
+ /**
+ * Checks if the given index is in range. If not, throws an appropriate
+ * runtime exception. This method does *not* check if the index is
+ * negative: It is always used immediately prior to an array access,
+ * which throws an ArrayIndexOutOfBoundsException if index is negative.
+ */
+ private void RangeCheck(int index) {
+ if (index >= size)
+ System.out.println("Array index out of bounds Exception Occured but cannot be thrown (not yet implemented)");
+ }
+}
projects / IRC.git / commitdiff