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package java.util; |
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/** |
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* An unbounded priority queue based on a priority heap. This queue orders |
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* An unbounded priority {@linkplain Queue queue} based on a priority heap. |
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* This queue orders |
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* elements according to an order specified at construction time, which is |
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* specified in the same manner as {@link java.util.TreeSet} and |
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* {@link java.util.TreeMap}: elements are ordered |
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/** |
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* Creates a <tt>PriorityQueue</tt> with the default initial capacity |
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* (11) that orders its elements according to their natural |
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* ordering (using <tt>Comparable</tt>.) |
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* ordering (using <tt>Comparable</tt>). |
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*/ |
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public PriorityQueue() { |
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this(DEFAULT_INITIAL_CAPACITY, null); |
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/** |
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* Creates a <tt>PriorityQueue</tt> with the specified initial capacity |
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* that orders its elements according to their natural ordering |
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* (using <tt>Comparable</tt>.) |
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* (using <tt>Comparable</tt>). |
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* |
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* @param initialCapacity the initial capacity for this priority queue. |
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* @throws IllegalArgumentException if <tt>initialCapacity</tt> is less |
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* than 1 |
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*/ |
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public PriorityQueue(int initialCapacity) { |
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this(initialCapacity, null); |
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* @throws IllegalArgumentException if <tt>initialCapacity</tt> is less |
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* than 1 |
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*/ |
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public PriorityQueue(int initialCapacity, Comparator<? super E> comparator) { |
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public PriorityQueue(int initialCapacity, |
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Comparator<? super E> comparator) { |
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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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* 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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* instance of a {@link SortedSet} or is another |
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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 sorted |
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* according to the same comparator, or according to its elements' |
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* natural order if the collection is sorted according to its |
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// Queue Methods |
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/** |
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* Add the specified element to this priority queue. |
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* |
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return (E) queue[1]; |
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} |
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// Collection Methods |
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// these first two override just to get the throws docs |
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// Collection Methods - the first two override to update docs |
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/** |
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* @throws NullPointerException if the specified element is <tt>null</tt>. |
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* Adds the specified element to this queue. |
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* @return <tt>true</tt> (as per the general contract of |
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* <tt>Collection.add</tt>). |
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* |
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* @throws NullPointerException {@inheritDoc} |
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* @throws ClassCastException if the specified element cannot be compared |
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* with elements currently in the priority queue according |
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* to the priority queue's ordering. |
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return super.add(o); |
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} |
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/** |
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* Adds all of the elements in the specified collection to this queue. |
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* The behavior of this operation is undefined if |
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* the specified collection is modified while the operation is in |
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* progress. (This implies that the behavior of this call is undefined if |
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* the specified collection is this queue, and this queue is nonempty.) |
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* <p> |
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* This implementation iterates over the specified collection, and adds |
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* each object returned by the iterator to this collection, in turn. |
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* @throws NullPointerException {@inheritDoc} |
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* @throws ClassCastException if any element cannot be compared |
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* with elements currently in the priority queue according |
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* to the priority queue's ordering. |
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* @throws NullPointerException if <tt>c</tt> or any element in <tt>c</tt> |
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* is <tt>null</tt> |
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*/ |
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public boolean addAll(Collection<? extends E> c) { |
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return super.addAll(c); |
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} |
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/** |
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* Removes a single instance of the specified element from this |
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* queue, if it is present. More formally, |
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* removes an element <tt>e</tt> such that <tt>(o==null ? e==null : |
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* o.equals(e))</tt>, if the queue contains one or more such |
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* elements. Returns <tt>true</tt> if the queue contained the |
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* specified element (or equivalently, if the queue changed as a |
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* result of the call). |
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* |
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* <p>This implementation iterates over the queue looking for the |
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* specified element. If it finds the element, it removes the element |
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* from the queue using the iterator's remove method.<p> |
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* |
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*/ |
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public boolean remove(Object o) { |
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if (o == null) |
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return false; |
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return false; |
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} |
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/** |
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* Returns an iterator over the elements in this queue. The iterator |
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* does not return the elements in any particular order. |
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* |
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* @return an iterator over the elements in this queue. |
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*/ |
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public Iterator<E> iterator() { |
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return new Itr(); |
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} |
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} |
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} |
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/** |
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* Returns the number of elements in this priority queue. |
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* |
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* @return the number of elements in this priority queue. |
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*/ |
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public int size() { |
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return size; |
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} |
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} |
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} |
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/** |
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* Returns the comparator used to order this collection, or <tt>null</tt> |
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* if this collection is sorted according to its elements natural ordering |
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* (using <tt>Comparable</tt>). |
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* |
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* @return the comparator used to order this collection, or <tt>null</tt> |
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* if this collection is sorted according to its elements natural ordering. |
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*/ |
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public Comparator<? super E> comparator() { |
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return comparator; |
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} |