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/* |
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* @(#)PriorityQueue.java 1.8 05/08/27 |
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* %W% %E% |
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* |
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* Copyright 2005 Sun Microsystems, Inc. All rights reserved. |
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* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. |
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private static final int DEFAULT_INITIAL_CAPACITY = 11; |
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/** |
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* Priority queue represented as a balanced binary heap: the two children |
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* of queue[n] are queue[2*n] and queue[2*n + 1]. The priority queue is |
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* ordered by comparator, or by the elements' natural ordering, if |
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* comparator is null: For each node n in the heap and each descendant d |
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* of n, n <= d. |
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* |
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* The element with the lowest value is in queue[1], assuming the queue is |
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* nonempty. (A one-based array is used in preference to the traditional |
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* zero-based array to simplify parent and child calculations.) |
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* |
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* queue.length must be >= 2, even if size == 0. |
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* Priority queue represented as a balanced binary heap: the two |
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* children of queue[n] are queue[2*n+1] and queue[2*(n+1)]. The |
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* priority queue is ordered by comparator, or by the elements' |
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* natural ordering, if comparator is null: For each node n in the |
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* heap and each descendant d of n, n <= d. The element with the |
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* lowest value is in queue[0], assuming the queue is nonempty. |
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*/ |
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private transient Object[] queue; |
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*/ |
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public PriorityQueue(int initialCapacity, |
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Comparator<? super E> comparator) { |
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// Note: This restriction of at least one is not actually needed, |
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// but continues for 1.5 compatibility |
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if (initialCapacity < 1) |
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throw new IllegalArgumentException(); |
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this.queue = new Object[initialCapacity + 1]; |
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this.queue = new Object[initialCapacity]; |
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this.comparator = comparator; |
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} |
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/** |
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* Common code to initialize underlying queue array across |
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* constructors below. |
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*/ |
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private void initializeArray(Collection<? extends E> c) { |
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int sz = c.size(); |
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int initialCapacity = (int)Math.min((sz * 110L) / 100, |
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Integer.MAX_VALUE - 1); |
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if (initialCapacity < 1) |
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initialCapacity = 1; |
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|
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this.queue = new Object[initialCapacity + 1]; |
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} |
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|
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/** |
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* Initially fill elements of the queue array under the |
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* knowledge that it is sorted or is another PQ, in which |
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* case we can just place the elements in the order presented. |
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*/ |
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private void fillFromSorted(Collection<? extends E> c) { |
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for (Iterator<? extends E> i = c.iterator(); i.hasNext(); ) { |
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int k = ++size; |
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if (k >= queue.length) |
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grow(k); |
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queue[k] = i.next(); |
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} |
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} |
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|
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/** |
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* Initially fill elements of the queue array that is not to our knowledge |
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* sorted, so we must rearrange the elements to guarantee the heap |
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* invariant. |
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*/ |
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private void fillFromUnsorted(Collection<? extends E> c) { |
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for (Iterator<? extends E> i = c.iterator(); i.hasNext(); ) { |
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int k = ++size; |
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if (k >= queue.length) |
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grow(k); |
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queue[k] = i.next(); |
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} |
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heapify(); |
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} |
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|
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/** |
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* Creates a <tt>PriorityQueue</tt> containing the elements in the |
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* specified collection. The priority queue has an initial |
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* capacity of 110% of the size of the specified collection or 1 |
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* if the collection is empty. If the specified collection is an |
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* specified collection. If the specified collection is an |
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* instance of a {@link java.util.SortedSet} or is another |
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* <tt>PriorityQueue</tt>, the priority queue will be ordered |
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* according to the same ordering. Otherwise, this priority queue |
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* of its elements are null |
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*/ |
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public PriorityQueue(Collection<? extends E> c) { |
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initializeArray(c); |
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if (c instanceof SortedSet) { |
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SortedSet<? extends E> s = (SortedSet<? extends E>)c; |
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comparator = (Comparator<? super E>)s.comparator(); |
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fillFromSorted(s); |
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} else if (c instanceof PriorityQueue) { |
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PriorityQueue<? extends E> s = (PriorityQueue<? extends E>) c; |
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comparator = (Comparator<? super E>)s.comparator(); |
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fillFromSorted(s); |
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} else { |
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initFromCollection(c); |
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if (c instanceof SortedSet) |
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comparator = (Comparator<? super E>) |
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((SortedSet<? extends E>)c).comparator(); |
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else if (c instanceof PriorityQueue) |
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comparator = (Comparator<? super E>) |
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((PriorityQueue<? extends E>)c).comparator(); |
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else { |
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comparator = null; |
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fillFromUnsorted(c); |
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heapify(); |
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} |
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} |
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|
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/** |
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* Creates a <tt>PriorityQueue</tt> containing the elements in the |
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* specified priority queue. The priority queue has an initial |
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* capacity of 110% of the size of the specified priority queue or |
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* 1 if the priority queue is empty. This priority queue will be |
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* specified priority queue. This priority queue will be |
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* ordered according to the same ordering as the given priority |
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* queue. |
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* |
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* of its elements are null |
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*/ |
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public PriorityQueue(PriorityQueue<? extends E> c) { |
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initializeArray(c); |
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comparator = (Comparator<? super E>)c.comparator(); |
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fillFromSorted(c); |
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initFromCollection(c); |
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} |
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|
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/** |
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* Creates a <tt>PriorityQueue</tt> containing the elements in the |
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* specified sorted set. The priority queue has an initial |
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* capacity of 110% of the size of the specified sorted set or 1 |
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* if the sorted set is empty. This priority queue will be ordered |
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* specified sorted set. This priority queue will be ordered |
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* according to the same ordering as the given sorted set. |
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* |
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* @param c the sorted set whose elements are to be placed |
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* of its elements are null |
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*/ |
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public PriorityQueue(SortedSet<? extends E> c) { |
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initializeArray(c); |
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comparator = (Comparator<? super E>)c.comparator(); |
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fillFromSorted(c); |
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initFromCollection(c); |
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} |
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/** |
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* Resize array, if necessary, to be able to hold given index. |
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* Initialize queue array with elements from the given Collection. |
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* @param c the collection |
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*/ |
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private void grow(int index) { |
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int newlen = queue.length; |
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if (index < newlen) // don't need to grow |
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return; |
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if (index == Integer.MAX_VALUE) |
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private void initFromCollection(Collection<? extends E> c) { |
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Object[] a = c.toArray(); |
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// If c.toArray incorrectly doesn't return Object[], copy it. |
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if (a.getClass() != Object[].class) |
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a = Arrays.copyOf(a, a.length, Object[].class); |
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queue = a; |
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size = a.length; |
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} |
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|
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/** |
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* Increases the capacity of the array. |
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* |
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* @param minCapacity the desired minimum capacity |
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*/ |
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private void grow(int minCapacity) { |
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if (minCapacity < 0) // overflow |
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throw new OutOfMemoryError(); |
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while (newlen <= index) { |
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if (newlen >= Integer.MAX_VALUE / 2) // avoid overflow |
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newlen = Integer.MAX_VALUE; |
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else |
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newlen <<= 2; |
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} |
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queue = Arrays.copyOf(queue, newlen); |
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int oldCapacity = queue.length; |
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// Double size if small; else grow by 50% |
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int newCapacity = ((oldCapacity < 64)? |
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((oldCapacity + 1) * 2): |
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((oldCapacity / 2) * 3)); |
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if (newCapacity < 0) // overflow |
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newCapacity = Integer.MAX_VALUE; |
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if (newCapacity < minCapacity) |
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newCapacity = minCapacity; |
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queue = Arrays.copyOf(queue, newCapacity); |
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} |
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/** |
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if (e == null) |
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throw new NullPointerException(); |
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modCount++; |
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++size; |
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|
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// Grow backing store if necessary |
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if (size >= queue.length) |
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grow(size); |
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|
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queue[size] = e; |
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fixUp(size); |
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int i = size; |
267 |
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if (i >= queue.length) |
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grow(i + 1); |
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size = i + 1; |
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if (i == 0) |
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queue[0] = e; |
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else |
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siftUp(i, e); |
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return true; |
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} |
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|
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public E peek() { |
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if (size == 0) |
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return null; |
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return (E) queue[1]; |
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return (E) queue[0]; |
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} |
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|
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private int indexOf(Object o) { |
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if (o == null) |
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return -1; |
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for (int i = 1; i <= size; i++) |
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if (o.equals(queue[i])) |
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return i; |
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if (o != null) { |
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for (int i = 0; i < size; i++) |
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if (o.equals(queue[i])) |
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return i; |
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} |
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return -1; |
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} |
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|
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} |
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|
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/** |
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* Version of remove using reference equality, not equals. |
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* Needed by iterator.remove |
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* |
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* @param o element to be removed from this queue, if present |
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* @return <tt>true</tt> if removed. |
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*/ |
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boolean removeEq(Object o) { |
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for (int i = 0; i < size; i++) { |
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if (o == queue[i]) { |
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removeAt(i); |
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return true; |
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} |
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} |
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return false; |
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} |
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|
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/** |
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* Returns <tt>true</tt> if this queue contains the specified element. |
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* More formally, returns <tt>true</tt> if and only if this queue contains |
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* at least one element <tt>e</tt> such that <tt>o.equals(e)</tt>. |
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* @return an array containing all of the elements in this queue. |
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*/ |
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public Object[] toArray() { |
352 |
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return Arrays.copyOfRange(queue, 1, size+1); |
352 |
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return Arrays.copyOf(queue, size); |
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} |
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|
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/** |
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public <T> T[] toArray(T[] a) { |
380 |
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if (a.length < size) |
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// Make a new array of a's runtime type, but my contents: |
382 |
< |
return (T[]) Arrays.copyOfRange(queue, 1, size+1, a.getClass()); |
383 |
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System.arraycopy(queue, 1, a, 0, size); |
382 |
> |
return (T[]) Arrays.copyOf(queue, size, a.getClass()); |
383 |
> |
System.arraycopy(queue, 0, a, 0, size); |
384 |
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if (a.length > size) |
385 |
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a[size] = null; |
386 |
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return a; |
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return new Itr(); |
397 |
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} |
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|
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private class Itr implements Iterator<E> { |
424 |
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|
399 |
> |
private final class Itr implements Iterator<E> { |
400 |
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/** |
401 |
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* Index (into queue array) of element to be returned by |
402 |
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* subsequent call to next. |
403 |
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*/ |
404 |
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private int cursor = 1; |
404 |
> |
private int cursor = 0; |
405 |
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|
406 |
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/** |
407 |
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* Index of element returned by most recent call to next, |
408 |
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* unless that element came from the forgetMeNot list. |
409 |
< |
* Reset to 0 if element is deleted by a call to remove. |
435 |
< |
*/ |
436 |
< |
private int lastRet = 0; |
437 |
< |
|
438 |
< |
/** |
439 |
< |
* The modCount value that the iterator believes that the backing |
440 |
< |
* List should have. If this expectation is violated, the iterator |
441 |
< |
* has detected concurrent modification. |
409 |
> |
* Set to -1 if element is deleted by a call to remove. |
410 |
|
*/ |
411 |
< |
private int expectedModCount = modCount; |
411 |
> |
private int lastRet = -1; |
412 |
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|
413 |
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/** |
414 |
< |
* A list of elements that were moved from the unvisited portion of |
414 |
> |
* A queue of elements that were moved from the unvisited portion of |
415 |
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* the heap into the visited portion as a result of "unlucky" element |
416 |
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* removals during the iteration. (Unlucky element removals are those |
417 |
< |
* that require a fixup instead of a fixdown.) We must visit all of |
417 |
> |
* that require a siftup instead of a siftdown.) We must visit all of |
418 |
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* the elements in this list to complete the iteration. We do this |
419 |
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* after we've completed the "normal" iteration. |
420 |
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* |
421 |
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* We expect that most iterations, even those involving removals, |
422 |
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* will not use need to store elements in this field. |
423 |
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*/ |
424 |
< |
private ArrayList<E> forgetMeNot = null; |
424 |
> |
private ArrayDeque<E> forgetMeNot = null; |
425 |
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|
426 |
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/** |
427 |
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* Element returned by the most recent call to next iff that |
428 |
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* element was drawn from the forgetMeNot list. |
429 |
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*/ |
430 |
< |
private Object lastRetElt = null; |
430 |
> |
private E lastRetElt = null; |
431 |
> |
|
432 |
> |
/** |
433 |
> |
* The modCount value that the iterator believes that the backing |
434 |
> |
* List should have. If this expectation is violated, the iterator |
435 |
> |
* has detected concurrent modification. |
436 |
> |
*/ |
437 |
> |
private int expectedModCount = modCount; |
438 |
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|
439 |
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public boolean hasNext() { |
440 |
< |
return cursor <= size || forgetMeNot != null; |
440 |
> |
return cursor < size || |
441 |
> |
(forgetMeNot != null && !forgetMeNot.isEmpty()); |
442 |
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} |
443 |
|
|
444 |
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public E next() { |
445 |
< |
checkForComodification(); |
446 |
< |
E result; |
447 |
< |
if (cursor <= size) { |
448 |
< |
result = (E) queue[cursor]; |
449 |
< |
lastRet = cursor++; |
450 |
< |
} |
451 |
< |
else if (forgetMeNot == null) |
452 |
< |
throw new NoSuchElementException(); |
453 |
< |
else { |
478 |
< |
int remaining = forgetMeNot.size(); |
479 |
< |
result = forgetMeNot.remove(remaining - 1); |
480 |
< |
if (remaining == 1) |
481 |
< |
forgetMeNot = null; |
482 |
< |
lastRet = 0; |
483 |
< |
lastRetElt = result; |
445 |
> |
if (expectedModCount != modCount) |
446 |
> |
throw new ConcurrentModificationException(); |
447 |
> |
if (cursor < size) |
448 |
> |
return (E) queue[lastRet = cursor++]; |
449 |
> |
if (forgetMeNot != null) { |
450 |
> |
lastRet = -1; |
451 |
> |
lastRetElt = forgetMeNot.poll(); |
452 |
> |
if (lastRetElt != null) |
453 |
> |
return lastRetElt; |
454 |
|
} |
455 |
< |
return result; |
455 |
> |
throw new NoSuchElementException(); |
456 |
|
} |
457 |
|
|
458 |
|
public void remove() { |
459 |
< |
checkForComodification(); |
460 |
< |
|
461 |
< |
if (lastRet != 0) { |
459 |
> |
if (expectedModCount != modCount) |
460 |
> |
throw new ConcurrentModificationException(); |
461 |
> |
if (lastRet == -1 && lastRetElt == null) |
462 |
> |
throw new IllegalStateException(); |
463 |
> |
if (lastRet != -1) { |
464 |
|
E moved = PriorityQueue.this.removeAt(lastRet); |
465 |
< |
lastRet = 0; |
466 |
< |
if (moved == null) { |
465 |
> |
lastRet = -1; |
466 |
> |
if (moved == null) |
467 |
|
cursor--; |
468 |
< |
} else { |
468 |
> |
else { |
469 |
|
if (forgetMeNot == null) |
470 |
< |
forgetMeNot = new ArrayList<E>(); |
470 |
> |
forgetMeNot = new ArrayDeque<E>(); |
471 |
|
forgetMeNot.add(moved); |
472 |
|
} |
501 |
– |
} else if (lastRetElt != null) { |
502 |
– |
PriorityQueue.this.remove(lastRetElt); |
503 |
– |
lastRetElt = null; |
473 |
|
} else { |
474 |
< |
throw new IllegalStateException(); |
474 |
> |
PriorityQueue.this.removeEq(lastRetElt); |
475 |
> |
lastRetElt = null; |
476 |
|
} |
507 |
– |
|
477 |
|
expectedModCount = modCount; |
478 |
|
} |
479 |
|
|
511 |
– |
final void checkForComodification() { |
512 |
– |
if (modCount != expectedModCount) |
513 |
– |
throw new ConcurrentModificationException(); |
514 |
– |
} |
480 |
|
} |
481 |
|
|
482 |
|
public int size() { |
489 |
|
*/ |
490 |
|
public void clear() { |
491 |
|
modCount++; |
492 |
< |
|
528 |
< |
// Null out element references to prevent memory leak |
529 |
< |
for (int i=1; i<=size; i++) |
492 |
> |
for (int i = 0; i < size; i++) |
493 |
|
queue[i] = null; |
531 |
– |
|
494 |
|
size = 0; |
495 |
|
} |
496 |
|
|
497 |
|
public E poll() { |
498 |
|
if (size == 0) |
499 |
|
return null; |
500 |
+ |
int s = --size; |
501 |
|
modCount++; |
502 |
< |
|
503 |
< |
E result = (E) queue[1]; |
504 |
< |
queue[1] = queue[size]; |
505 |
< |
queue[size--] = null; // Drop extra ref to prevent memory leak |
506 |
< |
if (size > 1) |
544 |
< |
fixDown(1); |
545 |
< |
|
502 |
> |
E result = (E)queue[0]; |
503 |
> |
E x = (E)queue[s]; |
504 |
> |
queue[s] = null; |
505 |
> |
if (s != 0) |
506 |
> |
siftDown(0, x); |
507 |
|
return result; |
508 |
|
} |
509 |
|
|
510 |
|
/** |
511 |
< |
* Removes and returns the ith element from queue. (Recall that queue |
551 |
< |
* is one-based, so 1 <= i <= size.) |
511 |
> |
* Removes the ith element from queue. |
512 |
|
* |
513 |
< |
* Normally this method leaves the elements at positions from 1 up to i-1, |
514 |
< |
* inclusive, untouched. Under these circumstances, it returns null. |
515 |
< |
* Occasionally, in order to maintain the heap invariant, it must move |
516 |
< |
* the last element of the list to some index in the range [2, i-1], |
517 |
< |
* and move the element previously at position (i/2) to position i. |
518 |
< |
* Under these circumstances, this method returns the element that was |
519 |
< |
* previously at the end of the list and is now at some position between |
520 |
< |
* 2 and i-1 inclusive. |
513 |
> |
* Normally this method leaves the elements at up to i-1, |
514 |
> |
* inclusive, untouched. Under these circumstances, it returns |
515 |
> |
* null. Occasionally, in order to maintain the heap invariant, |
516 |
> |
* it must swap a later element of the list with one earlier than |
517 |
> |
* i. Under these circumstances, this method returns the element |
518 |
> |
* that was previously at the end of the list and is now at some |
519 |
> |
* position before i. This fact is used by iterator.remove so as to |
520 |
> |
* avoid missing traverseing elements. |
521 |
|
*/ |
522 |
|
private E removeAt(int i) { |
523 |
< |
assert i > 0 && i <= size; |
523 |
> |
assert i >= 0 && i < size; |
524 |
|
modCount++; |
525 |
< |
|
526 |
< |
E moved = (E) queue[size]; |
527 |
< |
queue[i] = moved; |
528 |
< |
queue[size--] = null; // Drop extra ref to prevent memory leak |
529 |
< |
if (i <= size) { |
530 |
< |
fixDown(i); |
525 |
> |
int s = --size; |
526 |
> |
if (s == i) // removed last element |
527 |
> |
queue[i] = null; |
528 |
> |
else { |
529 |
> |
E moved = (E) queue[s]; |
530 |
> |
queue[s] = null; |
531 |
> |
siftDown(i, moved); |
532 |
|
if (queue[i] == moved) { |
533 |
< |
fixUp(i); |
533 |
> |
siftUp(i, moved); |
534 |
|
if (queue[i] != moved) |
535 |
|
return moved; |
536 |
|
} |
539 |
|
} |
540 |
|
|
541 |
|
/** |
542 |
< |
* Establishes the heap invariant (described above) assuming the heap |
543 |
< |
* satisfies the invariant except possibly for the leaf-node indexed by k |
544 |
< |
* (which may have a nextExecutionTime less than its parent's). |
545 |
< |
* |
546 |
< |
* This method functions by "promoting" queue[k] up the hierarchy |
547 |
< |
* (by swapping it with its parent) repeatedly until queue[k] |
548 |
< |
* is greater than or equal to its parent. |
549 |
< |
*/ |
550 |
< |
private void fixUp(int k) { |
551 |
< |
if (comparator == null) { |
552 |
< |
while (k > 1) { |
553 |
< |
int j = k >> 1; |
554 |
< |
if (((Comparable<? super E>)queue[j]).compareTo((E)queue[k]) <= 0) |
555 |
< |
break; |
556 |
< |
Object tmp = queue[j]; queue[j] = queue[k]; queue[k] = tmp; |
557 |
< |
k = j; |
558 |
< |
} |
559 |
< |
} else { |
560 |
< |
while (k > 1) { |
561 |
< |
int j = k >>> 1; |
562 |
< |
if (comparator.compare((E)queue[j], (E)queue[k]) <= 0) |
563 |
< |
break; |
564 |
< |
Object tmp = queue[j]; queue[j] = queue[k]; queue[k] = tmp; |
565 |
< |
k = j; |
566 |
< |
} |
567 |
< |
} |
568 |
< |
} |
569 |
< |
|
570 |
< |
/** |
571 |
< |
* Establishes the heap invariant (described above) in the subtree |
572 |
< |
* rooted at k, which is assumed to satisfy the heap invariant except |
573 |
< |
* possibly for node k itself (which may be greater than its children). |
574 |
< |
* |
575 |
< |
* This method functions by "demoting" queue[k] down the hierarchy |
576 |
< |
* (by swapping it with its smaller child) repeatedly until queue[k] |
577 |
< |
* is less than or equal to its children. |
578 |
< |
*/ |
579 |
< |
private void fixDown(int k) { |
580 |
< |
int j; |
581 |
< |
if (comparator == null) { |
582 |
< |
while ((j = k << 1) <= size && (j > 0)) { |
583 |
< |
if (j<size && |
584 |
< |
((Comparable<? super E>)queue[j]).compareTo((E)queue[j+1]) > 0) |
585 |
< |
j++; // j indexes smallest kid |
586 |
< |
|
587 |
< |
if (((Comparable<? super E>)queue[k]).compareTo((E)queue[j]) <= 0) |
588 |
< |
break; |
589 |
< |
Object tmp = queue[j]; queue[j] = queue[k]; queue[k] = tmp; |
590 |
< |
k = j; |
591 |
< |
} |
592 |
< |
} else { |
593 |
< |
while ((j = k << 1) <= size && (j > 0)) { |
594 |
< |
if (j<size && |
595 |
< |
comparator.compare((E)queue[j], (E)queue[j+1]) > 0) |
596 |
< |
j++; // j indexes smallest kid |
597 |
< |
if (comparator.compare((E)queue[k], (E)queue[j]) <= 0) |
598 |
< |
break; |
599 |
< |
Object tmp = queue[j]; queue[j] = queue[k]; queue[k] = tmp; |
600 |
< |
k = j; |
601 |
< |
} |
542 |
> |
* Inserts item x at position k, maintaining heap invariant by |
543 |
> |
* promoting x up the tree until it is greater than or equal to |
544 |
> |
* its parent, or is the root. |
545 |
> |
* |
546 |
> |
* To simplify and speed up coercions and comparisons. the |
547 |
> |
* Comparable and Comparator versions are separated into different |
548 |
> |
* methods that are otherwise identical. (Similarly for siftDown.) |
549 |
> |
* |
550 |
> |
* @param k the position to fill |
551 |
> |
* @param x the item to insert |
552 |
> |
*/ |
553 |
> |
private void siftUp(int k, E x) { |
554 |
> |
if (comparator != null) |
555 |
> |
siftUpUsingComparator(k, x); |
556 |
> |
else |
557 |
> |
siftUpComparable(k, x); |
558 |
> |
} |
559 |
> |
|
560 |
> |
private void siftUpComparable(int k, E x) { |
561 |
> |
Comparable<? super E> key = (Comparable<? super E>) x; |
562 |
> |
while (k > 0) { |
563 |
> |
int parent = (k - 1) >>> 1; |
564 |
> |
Object e = queue[parent]; |
565 |
> |
if (key.compareTo((E)e) >= 0) |
566 |
> |
break; |
567 |
> |
queue[k] = e; |
568 |
> |
k = parent; |
569 |
> |
} |
570 |
> |
queue[k] = key; |
571 |
> |
} |
572 |
> |
|
573 |
> |
private void siftUpUsingComparator(int k, E x) { |
574 |
> |
while (k > 0) { |
575 |
> |
int parent = (k - 1) >>> 1; |
576 |
> |
Object e = queue[parent]; |
577 |
> |
if (comparator.compare(x, (E)e) >= 0) |
578 |
> |
break; |
579 |
> |
queue[k] = e; |
580 |
> |
k = parent; |
581 |
> |
} |
582 |
> |
queue[k] = x; |
583 |
> |
} |
584 |
> |
|
585 |
> |
/** |
586 |
> |
* Inserts item x at position k, maintaining heap invariant by |
587 |
> |
* demoting x down the tree repeatedly until it is less than or |
588 |
> |
* equal to its children or is a leaf. |
589 |
> |
* |
590 |
> |
* @param k the position to fill |
591 |
> |
* @param x the item to insert |
592 |
> |
*/ |
593 |
> |
private void siftDown(int k, E x) { |
594 |
> |
if (comparator != null) |
595 |
> |
siftDownUsingComparator(k, x); |
596 |
> |
else |
597 |
> |
siftDownComparable(k, x); |
598 |
> |
} |
599 |
> |
|
600 |
> |
private void siftDownComparable(int k, E x) { |
601 |
> |
Comparable<? super E> key = (Comparable<? super E>)x; |
602 |
> |
int half = size >>> 1; // loop while a non-leaf |
603 |
> |
while (k < half) { |
604 |
> |
int child = (k << 1) + 1; // assume left child is least |
605 |
> |
Object c = queue[child]; |
606 |
> |
int right = child + 1; |
607 |
> |
if (right < size && |
608 |
> |
((Comparable<? super E>)c).compareTo((E)queue[right]) > 0) |
609 |
> |
c = queue[child = right]; |
610 |
> |
if (key.compareTo((E)c) <= 0) |
611 |
> |
break; |
612 |
> |
queue[k] = c; |
613 |
> |
k = child; |
614 |
> |
} |
615 |
> |
queue[k] = key; |
616 |
> |
} |
617 |
> |
|
618 |
> |
private void siftDownUsingComparator(int k, E x) { |
619 |
> |
int half = size >>> 1; |
620 |
> |
while (k < half) { |
621 |
> |
int child = (k << 1) + 1; |
622 |
> |
Object c = queue[child]; |
623 |
> |
int right = child + 1; |
624 |
> |
if (right < size && |
625 |
> |
comparator.compare((E)c, (E)queue[right]) > 0) |
626 |
> |
c = queue[child = right]; |
627 |
> |
if (comparator.compare(x, (E)c) <= 0) |
628 |
> |
break; |
629 |
> |
queue[k] = c; |
630 |
> |
k = child; |
631 |
|
} |
632 |
+ |
queue[k] = x; |
633 |
|
} |
634 |
|
|
635 |
|
/** |
637 |
|
* assuming nothing about the order of the elements prior to the call. |
638 |
|
*/ |
639 |
|
private void heapify() { |
640 |
< |
for (int i = size/2; i >= 1; i--) |
641 |
< |
fixDown(i); |
640 |
> |
for (int i = (size >>> 1) - 1; i >= 0; i--) |
641 |
> |
siftDown(i, (E)queue[i]); |
642 |
|
} |
643 |
|
|
644 |
|
/** |
669 |
|
s.defaultWriteObject(); |
670 |
|
|
671 |
|
// Write out array length |
672 |
< |
s.writeInt(queue.length); |
672 |
> |
// For compatibility with 1.5 version, must be at least 2. |
673 |
> |
s.writeInt(Math.max(2, queue.length)); |
674 |
|
|
675 |
|
// Write out all elements in the proper order. |
676 |
< |
for (int i=1; i<=size; i++) |
676 |
> |
for (int i=0; i<size; i++) |
677 |
|
s.writeObject(queue[i]); |
678 |
|
} |
679 |
|
|
692 |
|
queue = new Object[arrayLength]; |
693 |
|
|
694 |
|
// Read in all elements in the proper order. |
695 |
< |
for (int i=1; i<=size; i++) |
695 |
> |
for (int i=0; i<size; i++) |
696 |
|
queue[i] = (E) s.readObject(); |
697 |
|
} |
698 |
|
|