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/** |
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* An unbounded priority queue based on a priority heap. 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 TreeSet} and {@link TreeMap}: |
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* elements are ordered |
6 |
> |
* 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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* either according to their <i>natural order</i> (see {@link Comparable}), or |
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< |
* according to a {@link Comparator}, depending on which constructor is used. |
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* The <em>head</em> of this queue is the least element with respect to the |
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* specified ordering. If multiple elements are tied for least value, the |
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> |
* according to a {@link java.util.Comparator}, depending on which |
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> |
* constructor is used. |
11 |
> |
* <p>The <em>head</em> of this queue is the <em>least</em> element with |
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> |
* respect to the specified ordering. |
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> |
* If multiple elements are tied for least value, the |
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* head is one of those elements. A priority queue does not permit |
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* <tt>null</tt> elements. |
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* |
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* |
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* <p>A priority queue has a <i>capacity</i>. The capacity is the |
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* size of the array used internally to store the elements on the |
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* queue. It is always at least as large as the queue size. As |
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> |
* queue. |
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> |
* It is always at least as large as the queue size. As |
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* elements are added to a priority queue, its capacity grows |
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* automatically. The details of the growth policy are not specified. |
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* |
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* @author Josh Bloch |
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*/ |
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public class PriorityQueue<E> extends AbstractQueue<E> |
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< |
implements Queue<E>, java.io.Serializable { |
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> |
implements Sorted, Queue<E>, java.io.Serializable { |
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|
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private static final int DEFAULT_INITIAL_CAPACITY = 11; |
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|
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private transient int modCount = 0; |
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|
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/** |
81 |
< |
* Create a <tt>PriorityQueue</tt> with the default initial capacity |
81 |
> |
* 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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*/ |
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} |
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|
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/** |
90 |
< |
* Create a <tt>PriorityQueue</tt> with the specified initial capacity |
90 |
> |
* 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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* |
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} |
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|
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/** |
101 |
< |
* Create a <tt>PriorityQueue</tt> with the specified initial capacity |
101 |
> |
* Creates a <tt>PriorityQueue</tt> with the specified initial capacity |
102 |
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* that orders its elements according to the specified comparator. |
103 |
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* |
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* @param initialCapacity the initial capacity for this priority queue. |
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} |
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|
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/** |
119 |
< |
* Create a <tt>PriorityQueue</tt> containing the elements in the specified |
120 |
< |
* collection. The priority queue has an initial capacity of 110% of the |
121 |
< |
* size of the specified collection; or 1 if the collection is empty. |
119 |
> |
* Creates a <tt>PriorityQueue</tt> containing the elements in the |
120 |
> |
* specified collection. |
121 |
> |
* The priority queue has an initial capacity of 110% of the |
122 |
> |
* size of the specified collection or 1 if the collection is empty. |
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|
* If the specified collection |
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* implements the {@link Sorted} interface, the priority queue will be |
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* sorted according to the same comparator, or according to its elements' |
146 |
|
this.queue = new Object[initialCapacity + 1]; |
147 |
|
|
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|
if (c instanceof Sorted) { |
149 |
< |
// FIXME: this code assumes too much |
146 |
< |
this.comparator = (Comparator<? super E>) ((Sorted)c).comparator(); |
147 |
< |
for (Iterator<? extends E> i = c.iterator(); i.hasNext(); ) |
148 |
< |
queue[++size] = i.next(); |
149 |
> |
comparator = (Comparator<? super E>)((Sorted)c).comparator(); |
150 |
|
} else { |
151 |
|
comparator = null; |
151 |
– |
for (Iterator<? extends E> i = c.iterator(); i.hasNext(); ) |
152 |
– |
add(i.next()); |
152 |
|
} |
153 |
+ |
|
154 |
+ |
for (Iterator<? extends E> i = c.iterator(); i.hasNext(); ) |
155 |
+ |
add(i.next()); |
156 |
|
} |
157 |
|
|
158 |
|
// Queue Methods |
160 |
|
/** |
161 |
|
* Add the specified element to this priority queue. |
162 |
|
* |
161 |
– |
* @param element the element to add. |
163 |
|
* @return <tt>true</tt> |
164 |
|
* @throws ClassCastException if the specified element cannot be compared |
165 |
|
* with elements currently in the priority queue according |
166 |
|
* to the priority queue's ordering. |
167 |
< |
* @throws NullPointerException if the specified element is null. |
167 |
> |
* @throws NullPointerException if the specified element is <tt>null</tt>. |
168 |
|
*/ |
169 |
< |
public boolean offer(E element) { |
170 |
< |
if (element == null) |
169 |
> |
public boolean offer(E o) { |
170 |
> |
if (o == null) |
171 |
|
throw new NullPointerException(); |
172 |
|
modCount++; |
173 |
|
++size; |
179 |
|
queue = newQueue; |
180 |
|
} |
181 |
|
|
182 |
< |
queue[size] = element; |
182 |
> |
queue[size] = o; |
183 |
|
fixUp(size); |
184 |
|
return true; |
185 |
|
} |
204 |
|
* with elements currently in the priority queue according |
205 |
|
* to the priority queue's ordering. |
206 |
|
*/ |
207 |
< |
public boolean add(E element) { |
208 |
< |
return super.add(element); |
207 |
> |
public boolean add(E o) { |
208 |
> |
return super.add(o); |
209 |
|
} |
210 |
|
|
211 |
|
/** |
211 |
– |
* @throws NullPointerException if any element is <tt>null</tt>. |
212 |
|
* @throws ClassCastException if any element cannot be compared |
213 |
|
* with elements currently in the priority queue according |
214 |
|
* to the priority queue's ordering. |
215 |
+ |
* @throws NullPointerException if <tt>c</tt> or any element in <tt>c</tt> |
216 |
+ |
* is <tt>null</tt> |
217 |
|
*/ |
218 |
|
public boolean addAll(Collection<? extends E> c) { |
219 |
|
return super.addAll(c); |