Adding JMCR-Stable version

[Benchmarks_CSolver.git] / JMCR-Stable / mcr-engine / src / edu / tamu / aser / mcr / graph / Queue.java

diff --git a/JMCR-Stable/mcr-engine/src/edu/tamu/aser/mcr/graph/Queue.java b/JMCR-Stable/mcr-engine/src/edu/tamu/aser/mcr/graph/Queue.java
new file mode 100755 (executable)
index 0000000..090cc4e
--- /dev/null
+++ b/JMCR-Stable/mcr-engine/src/edu/tamu/aser/mcr/graph/Queue.java
@@ -0,0 +1,163 @@
+/*******************************************************************************
+ * Copyright (c) 2013 University of Illinois
+ * 
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * 
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ ******************************************************************************/
+package edu.tamu.aser.mcr.graph;
+/*************************************************************************
+ *  Compilation:  javac Queue.java
+ *  Execution:    java Queue < input.txt
+ *  Data files:   http://algs4.cs.princeton.edu/13stacks/tobe.txt  
+ *
+ *  A generic queue, implemented using a linked list.
+ *
+ *  % java Queue < tobe.txt 
+ *  to be or not to be (2 left on queue)
+ *
+ *************************************************************************/
+
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
+/**
+ *  The <tt>Queue</tt> class represents a first-in-first-out (FIFO)
+ *  queue of generic items.
+ *  It supports the usual <em>enqueue</em> and <em>dequeue</em>
+ *  operations, along with methods for peeking at the top item,
+ *  testing if the queue is empty, and iterating through
+ *  the items in FIFO order.
+ *  <p>
+ *  All queue operations except iteration are constant time.
+ *  <p>
+ *  For additional documentation, see <a href="http://introcs.cs.princeton.edu/43stack">Section 4.3</a> of
+ *  <i>Introduction to Programming in Java: An Interdisciplinary Approach</i> by Robert Sedgewick and Kevin Wayne.
+ */
+public class Queue<Item> implements Iterable<Item> {
+    private int N;         // number of elements on queue
+    private Node first;    // beginning of queue
+    private Node last;     // end of queue
+
+    // helper linked list class
+    private class Node {
+        private Item item;
+        private Node next;
+    }
+
+   /**
+     * Create an empty queue.
+     */
+    public Queue() {
+        first = null;
+        last  = null;
+    }
+
+   /**
+     * Is the queue empty?
+     */
+    public boolean isEmpty() {
+        return first == null;
+    }
+
+   /**
+     * Return the number of items in the queue.
+     */
+    public int size() {
+        return N;     
+    }
+
+   /**
+     * Return the number of items in the queue.
+     */
+    public int length() {
+        return N;     
+    }
+
+   /**
+     * Return the item least recently added to the queue.
+     * Throw an exception if the queue is empty.
+     */
+    public Item peek() {
+        if (isEmpty()) throw new RuntimeException("Queue underflow");
+        return first.item;
+    }
+
+   /**
+     * Add the item to the queue.
+     */
+    public void enqueue(Item item) {
+        Node x = new Node();
+        x.item = item;
+        if (isEmpty()) { first = x;     last = x; }
+        else           { last.next = x; last = x; }
+        N++;
+    }
+
+   /**
+     * Remove and return the item on the queue least recently added.
+     * Throw an exception if the queue is empty.
+     */
+    public Item dequeue() {
+        if (isEmpty()) throw new RuntimeException("Queue underflow");
+        Item item = first.item;
+        first = first.next;
+        N--;
+        if (isEmpty()) last = null;   // to avoid loitering
+        return item;
+    }
+
+   /**
+     * Return string representation.
+     */
+    public String toString() {
+        StringBuilder s = new StringBuilder();
+        for (Item item : this)
+            s.append(item + " ");
+        return s.toString();
+    } 
+ 
+
+   /**
+     * Return an iterator that iterates over the items on the queue in FIFO order.
+     */
+    public Iterator<Item> iterator()  {
+        return new ListIterator();  
+    }
+
+    // an iterator, doesn't implement remove() since it's optional
+    private class ListIterator implements Iterator<Item> {
+        private Node current = first;
+
+        public boolean hasNext()  { return current != null;                     }
+        public void remove()      { throw new UnsupportedOperationException();  }
+
+        public Item next() {
+            if (!hasNext()) throw new NoSuchElementException();
+            Item item = current.item;
+            current = current.next; 
+            return item;
+        }
+    }
+}