Made Heap, List, Queue, and Stack Iterable

git-svn-id: https://java-algorithms-implementation.googlecode.com/svn/trunk@401 032fbc0f-8cab-eb90-e552-f08422b9a96a

Author: phishman3579

src/com/jwetherell/algorithms/data_structures/BinaryHeap.java

@@ -2,6 +2,7 @@
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Iterator;
 import java.util.List;
 
 /**
@@ -17,7 +18,7 @@
  * 
  * @author Justin Wetherell <phishman3579@gmail.com>
  */
-public abstract class BinaryHeap<T extends Comparable<T>> {
+public abstract class BinaryHeap<T extends Comparable<T>> implements Iterable<T> {
 
     public enum HeapType {
         Tree, Array
@@ -428,6 +429,52 @@ private static <T extends Comparable<T>> String getString(BinaryHeapArray<T> tre
                 return builder.toString();
             }
         }
+
+        /**
+         * {@inheritDoc}
+         * 
+         * This iterator will copy the entire data structure and sort it. Be aware!
+         */
+        @Override
+        public Iterator<T> iterator() {
+            return (new BinaryHeapArrayIterator<T>(this));
+        }
+
+        private static class BinaryHeapArrayIterator<T extends Comparable<T>> implements Iterator<T> {
+
+            private T[] array = null;
+            private int index = 0;
+
+            private BinaryHeapArrayIterator(BinaryHeapArray<T> heap) {
+                this.array = heap.getHeap();
+                Arrays.sort(array);
+            }
+
+            /**
+             * {@inheritDoc}
+             */
+            @Override
+            public boolean hasNext() {
+                return (index<array.length);
+            }
+
+            /**
+             * {@inheritDoc}
+             */
+            @Override
+            public T next() {
+                if (index>=array.length) return null;
+                return array[index++];
+            }
+
+            /**
+             * {@inheritDoc}
+             */
+            @Override
+            public void remove() {
+                System.err.println("OperationNotSupported");
+            }
+        }
     }
 
     public static class BinaryHeapTree<T extends Comparable<T>> extends BinaryHeap<T> {
@@ -949,5 +996,51 @@ public String toString() {
                         + ((left != null) ? left.value : "NULL") + " right=" + ((right != null) ? right.value : "NULL");
             }
         }
+
+        /**
+         * {@inheritDoc}
+         * 
+         * This iterator will copy the entire data structure and sort it. Be aware!
+         */
+        @Override
+        public Iterator<T> iterator() {
+            return (new BinaryHeapTreeIterator<T>(this));
+        }
+
+        private static class BinaryHeapTreeIterator<T extends Comparable<T>> implements Iterator<T> {
+
+            private T[] array = null;
+            private int index = 0;
+
+            private BinaryHeapTreeIterator(BinaryHeapTree<T> heap) {
+                array = heap.getHeap();
+                Arrays.sort(array);
+            }
+
+            /**
+             * {@inheritDoc}
+             */
+            @Override
+            public boolean hasNext() {
+                return (index<array.length);
+            }
+
+            /**
+             * {@inheritDoc}
+             */
+            @Override
+            public T next() {
+                if (index>=array.length) return null;
+                return array[index++];
+            }
+
+            /**
+             * {@inheritDoc}
+             */
+            @Override
+            public void remove() {
+                System.err.println("OperationNotSupported");
+            }
+        }
     }
 }

src/com/jwetherell/algorithms/data_structures/List.java

@@ -165,6 +165,8 @@ public String toString() {
 
         /**
          * {@inheritDoc}
+         * 
+         * This iterator is NOT thread safe and is invalid when the data structure is modified.
          */
         @Override
         public Iterator<T> iterator() {
@@ -359,6 +361,8 @@ public String toString() {
 
         /**
          * {@inheritDoc}
+         * 
+         * This iterator is NOT thread safe and is invalid when the data structure is modified.
          */
         @Override
         public Iterator<T> iterator() {

src/com/jwetherell/algorithms/data_structures/Queue.java

@@ -158,6 +158,11 @@ public String toString() {
             return builder.toString();
         }
 
+        /**
+         * {@inheritDoc}
+         * 
+         * This iterator is NOT thread safe and is invalid when the data structure is modified.
+         */
         @Override
         public Iterator<T> iterator() {
             return (new ArrayQueueIterator<T>(this));
@@ -328,6 +333,8 @@ public String toString() {
 
         /**
          * {@inheritDoc}
+         * 
+         * This iterator is NOT thread safe and is invalid when the data structure is modified.
          */
         @Override
         public Iterator<T> iterator() {

src/com/jwetherell/algorithms/data_structures/Stack.java

@@ -139,6 +139,8 @@ public String toString() {
 
         /**
          * {@inheritDoc}
+         * 
+         * This iterator is NOT thread safe and is invalid when the data structure is modified.
          */
         @Override
         public Iterator<T> iterator() {
@@ -299,6 +301,8 @@ public String toString() {
 
         /**
          * {@inheritDoc}
+         * 
+         * This iterator is NOT thread safe and is invalid when the data structure is modified.
          */
         @Override
         public Iterator<T> iterator() {