3 |
|
/** |
4 |
|
* An unbounded priority queue based on a priority heap. This queue orders |
5 |
|
* elements according to an order specified at construction time, which is |
6 |
< |
* specified in the same manner as {@link TreeSet} and {@link TreeMap}: elements are ordered |
6 |
> |
* specified in the same manner as {@link java.util.TreeSet} and |
7 |
> |
* {@link java.util.TreeMap}: elements are ordered |
8 |
|
* either according to their <i>natural order</i> (see {@link Comparable}), or |
9 |
< |
* according to a {@link Comparator}, depending on which constructor is used. |
10 |
< |
* The {@link #peek}, {@link #poll}, and {@link #remove} methods return the |
11 |
< |
* minimal element with respect to the specified ordering. If multiple |
12 |
< |
* elements are tied for least value, no guarantees are made as to |
13 |
< |
* which of these elements is returned. |
9 |
> |
* according to a {@link java.util.Comparator}, depending on which |
10 |
> |
* constructor is used. |
11 |
> |
* <p>The <em>head</em> of this queue is the <em>least</em> element with |
12 |
> |
* respect to the specified ordering. |
13 |
> |
* If multiple elements are tied for least value, the |
14 |
> |
* head is one of those elements. A priority queue does not permit |
15 |
> |
* <tt>null</tt> elements. |
16 |
> |
* |
17 |
> |
* <p>The {@link #remove()} and {@link #poll()} methods remove and |
18 |
> |
* return the head of the queue. |
19 |
> |
* |
20 |
> |
* <p>The {@link #element()} and {@link #peek()} methods return, but do |
21 |
> |
* not delete, the head of the queue. |
22 |
|
* |
23 |
|
* <p>A priority queue has a <i>capacity</i>. The capacity is the |
24 |
|
* size of the array used internally to store the elements on the |
25 |
< |
* queue. It is always at least as large as the queue size. As |
25 |
> |
* queue. |
26 |
> |
* It is always at least as large as the queue size. As |
27 |
|
* elements are added to a priority queue, its capacity grows |
28 |
|
* automatically. The details of the growth policy are not specified. |
29 |
|
* |
30 |
< |
*<p>Implementation note: this implementation provides O(log(n)) time |
31 |
< |
*for the insertion methods (<tt>offer</tt>, <tt>poll</tt>, |
32 |
< |
*<tt>remove()</tt> and <tt>add</tt>) methods; linear time for the |
33 |
< |
*<tt>remove(Object)</tt> and <tt>contains(Object)</tt> methods; and |
34 |
< |
*constant time for the retrieval methods (<tt>peek</tt>, |
35 |
< |
*<tt>element</tt>, and <tt>size</tt>). |
30 |
> |
* <p>Implementation note: this implementation provides O(log(n)) time |
31 |
> |
* for the insertion methods (<tt>offer</tt>, <tt>poll</tt>, |
32 |
> |
* <tt>remove()</tt> and <tt>add</tt>) methods; linear time for the |
33 |
> |
* <tt>remove(Object)</tt> and <tt>contains(Object)</tt> methods; and |
34 |
> |
* constant time for the retrieval methods (<tt>peek</tt>, |
35 |
> |
* <tt>element</tt>, and <tt>size</tt>). |
36 |
|
* |
37 |
|
* <p>This class is a member of the |
38 |
|
* <a href="{@docRoot}/../guide/collections/index.html"> |
41 |
|
* @author Josh Bloch |
42 |
|
*/ |
43 |
|
public class PriorityQueue<E> extends AbstractQueue<E> |
44 |
< |
implements Queue<E>, |
45 |
< |
java.io.Serializable { |
44 |
> |
implements Queue<E>, java.io.Serializable { |
45 |
> |
|
46 |
|
private static final int DEFAULT_INITIAL_CAPACITY = 11; |
47 |
|
|
48 |
|
/** |
58 |
|
* |
59 |
|
* queue.length must be >= 2, even if size == 0. |
60 |
|
*/ |
61 |
< |
private transient E[] queue; |
61 |
> |
private transient Object[] queue; |
62 |
|
|
63 |
|
/** |
64 |
|
* The number of elements in the priority queue. |
69 |
|
* The comparator, or null if priority queue uses elements' |
70 |
|
* natural ordering. |
71 |
|
*/ |
72 |
< |
private final Comparator<E> comparator; |
72 |
> |
private final Comparator<? super E> comparator; |
73 |
|
|
74 |
|
/** |
75 |
|
* The number of times this priority queue has been |
78 |
|
private transient int modCount = 0; |
79 |
|
|
80 |
|
/** |
81 |
< |
* Create a new priority queue with the default initial capacity |
81 |
> |
* Creates a <tt>PriorityQueue</tt> with the default initial capacity |
82 |
|
* (11) that orders its elements according to their natural |
83 |
|
* ordering (using <tt>Comparable</tt>.) |
84 |
|
*/ |
85 |
|
public PriorityQueue() { |
86 |
< |
this(DEFAULT_INITIAL_CAPACITY); |
86 |
> |
this(DEFAULT_INITIAL_CAPACITY, null); |
87 |
|
} |
88 |
|
|
89 |
|
/** |
90 |
< |
* Create a new priority queue with the specified initial capacity |
90 |
> |
* Creates a <tt>PriorityQueue</tt> with the specified initial capacity |
91 |
|
* that orders its elements according to their natural ordering |
92 |
|
* (using <tt>Comparable</tt>.) |
93 |
|
* |
98 |
|
} |
99 |
|
|
100 |
|
/** |
101 |
< |
* Create a new priority queue with the specified initial capacity (11) |
101 |
> |
* Creates a <tt>PriorityQueue</tt> with the specified initial capacity |
102 |
|
* that orders its elements according to the specified comparator. |
103 |
|
* |
104 |
|
* @param initialCapacity the initial capacity for this priority queue. |
105 |
|
* @param comparator the comparator used to order this priority queue. |
106 |
+ |
* If <tt>null</tt> then the order depends on the elements' natural |
107 |
+ |
* ordering. |
108 |
+ |
* @throws IllegalArgumentException if <tt>initialCapacity</tt> is less |
109 |
+ |
* than 1 |
110 |
|
*/ |
111 |
< |
public PriorityQueue(int initialCapacity, Comparator<E> comparator) { |
111 |
> |
public PriorityQueue(int initialCapacity, Comparator<? super E> comparator) { |
112 |
|
if (initialCapacity < 1) |
113 |
< |
initialCapacity = 1; |
114 |
< |
queue = new E[initialCapacity + 1]; |
113 |
> |
throw new IllegalArgumentException(); |
114 |
> |
this.queue = new Object[initialCapacity + 1]; |
115 |
|
this.comparator = comparator; |
116 |
|
} |
117 |
|
|
118 |
|
/** |
119 |
< |
* Create a new priority queue containing the elements in the specified |
120 |
< |
* collection. The priority queue has an initial capacity of 110% of the |
107 |
< |
* size of the specified collection. If the specified collection |
108 |
< |
* implements the {@link Sorted} interface, the priority queue will be |
109 |
< |
* sorted according to the same comparator, or according to its elements' |
110 |
< |
* natural order if the collection is sorted according to its elements' |
111 |
< |
* natural order. If the specified collection does not implement |
112 |
< |
* <tt>Sorted</tt>, the priority queue is ordered according to |
113 |
< |
* its elements' natural order. |
114 |
< |
* |
115 |
< |
* @param initialElements the collection whose elements are to be placed |
116 |
< |
* into this priority queue. |
117 |
< |
* @throws ClassCastException if elements of the specified collection |
118 |
< |
* cannot be compared to one another according to the priority |
119 |
< |
* queue's ordering. |
120 |
< |
* @throws NullPointerException if the specified collection or an |
121 |
< |
* element of the specified collection is <tt>null</tt>. |
119 |
> |
* Common code to initialize underlying queue array across |
120 |
> |
* constructors below. |
121 |
|
*/ |
122 |
< |
public PriorityQueue(Collection<E> initialElements) { |
123 |
< |
int sz = initialElements.size(); |
122 |
> |
private void initializeArray(Collection<? extends E> c) { |
123 |
> |
int sz = c.size(); |
124 |
|
int initialCapacity = (int)Math.min((sz * 110L) / 100, |
125 |
|
Integer.MAX_VALUE - 1); |
126 |
|
if (initialCapacity < 1) |
127 |
|
initialCapacity = 1; |
129 |
– |
queue = new E[initialCapacity + 1]; |
128 |
|
|
129 |
+ |
this.queue = new Object[initialCapacity + 1]; |
130 |
+ |
} |
131 |
|
|
132 |
< |
if (initialElements instanceof Sorted) { |
133 |
< |
comparator = ((Sorted)initialElements).comparator(); |
134 |
< |
for (Iterator<E> i = initialElements.iterator(); i.hasNext(); ) |
135 |
< |
queue[++size] = i.next(); |
136 |
< |
} else { |
132 |
> |
/** |
133 |
> |
* Initially fill elements of the queue array under the |
134 |
> |
* knowledge that it is sorted or is another PQ, in which |
135 |
> |
* case we can just place the elements without fixups. |
136 |
> |
*/ |
137 |
> |
private void fillFromSorted(Collection<? extends E> c) { |
138 |
> |
for (Iterator<? extends E> i = c.iterator(); i.hasNext(); ) |
139 |
> |
queue[++size] = i.next(); |
140 |
> |
} |
141 |
> |
|
142 |
> |
|
143 |
> |
/** |
144 |
> |
* Initially fill elements of the queue array that is |
145 |
> |
* not to our knowledge sorted, so we must add them |
146 |
> |
* one by one. |
147 |
> |
*/ |
148 |
> |
private void fillFromUnsorted(Collection<? extends E> c) { |
149 |
> |
for (Iterator<? extends E> i = c.iterator(); i.hasNext(); ) |
150 |
> |
add(i.next()); |
151 |
> |
} |
152 |
> |
|
153 |
> |
/** |
154 |
> |
* Creates a <tt>PriorityQueue</tt> containing the elements in the |
155 |
> |
* specified collection. The priority queue has an initial |
156 |
> |
* capacity of 110% of the size of the specified collection or 1 |
157 |
> |
* if the collection is empty. If the specified collection is an |
158 |
> |
* instance of a {@link SortedSet} or is another |
159 |
> |
* <tt>PriorityQueue</tt>, the priority queue will be sorted |
160 |
> |
* according to the same comparator, or according to its elements' |
161 |
> |
* natural order if the collection is sorted according to its |
162 |
> |
* elements' natural order. Otherwise, the priority queue is |
163 |
> |
* ordered according to its elements' natural order. |
164 |
> |
* |
165 |
> |
* @param c the collection whose elements are to be placed |
166 |
> |
* into this priority queue. |
167 |
> |
* @throws ClassCastException if elements of the specified collection |
168 |
> |
* cannot be compared to one another according to the priority |
169 |
> |
* queue's ordering. |
170 |
> |
* @throws NullPointerException if <tt>c</tt> or any element within it |
171 |
> |
* is <tt>null</tt> |
172 |
> |
*/ |
173 |
> |
public PriorityQueue(Collection<? extends E> c) { |
174 |
> |
initializeArray(c); |
175 |
> |
if (c instanceof SortedSet<? extends E>) { |
176 |
> |
SortedSet<? extends E> s = (SortedSet<? extends E>) c; |
177 |
> |
comparator = (Comparator<? super E>)s.comparator(); |
178 |
> |
fillFromSorted(s); |
179 |
> |
} |
180 |
> |
else if (c instanceof PriorityQueue<? extends E>) { |
181 |
> |
PriorityQueue<? extends E> s = (PriorityQueue<? extends E>) c; |
182 |
> |
comparator = (Comparator<? super E>)s.comparator(); |
183 |
> |
fillFromSorted(s); |
184 |
> |
} |
185 |
> |
else { |
186 |
|
comparator = null; |
187 |
< |
for (Iterator<E> i = initialElements.iterator(); i.hasNext(); ) |
139 |
< |
add(i.next()); |
187 |
> |
fillFromUnsorted(c); |
188 |
|
} |
189 |
|
} |
190 |
|
|
191 |
+ |
/** |
192 |
+ |
* Creates a <tt>PriorityQueue</tt> containing the elements in the |
193 |
+ |
* specified collection. The priority queue has an initial |
194 |
+ |
* capacity of 110% of the size of the specified collection or 1 |
195 |
+ |
* if the collection is empty. This priority queue will be sorted |
196 |
+ |
* according to the same comparator as the given collection, or |
197 |
+ |
* according to its elements' natural order if the collection is |
198 |
+ |
* sorted according to its elements' natural order. |
199 |
+ |
* |
200 |
+ |
* @param c the collection whose elements are to be placed |
201 |
+ |
* into this priority queue. |
202 |
+ |
* @throws ClassCastException if elements of the specified collection |
203 |
+ |
* cannot be compared to one another according to the priority |
204 |
+ |
* queue's ordering. |
205 |
+ |
* @throws NullPointerException if <tt>c</tt> or any element within it |
206 |
+ |
* is <tt>null</tt> |
207 |
+ |
*/ |
208 |
+ |
public PriorityQueue(PriorityQueue<? extends E> c) { |
209 |
+ |
initializeArray(c); |
210 |
+ |
comparator = (Comparator<? super E>)c.comparator(); |
211 |
+ |
fillFromSorted(c); |
212 |
+ |
} |
213 |
+ |
|
214 |
+ |
/** |
215 |
+ |
* Creates a <tt>PriorityQueue</tt> containing the elements in the |
216 |
+ |
* specified collection. The priority queue has an initial |
217 |
+ |
* capacity of 110% of the size of the specified collection or 1 |
218 |
+ |
* if the collection is empty. This priority queue will be sorted |
219 |
+ |
* according to the same comparator as the given collection, or |
220 |
+ |
* according to its elements' natural order if the collection is |
221 |
+ |
* sorted according to its elements' natural order. |
222 |
+ |
* |
223 |
+ |
* @param c the collection whose elements are to be placed |
224 |
+ |
* into this priority queue. |
225 |
+ |
* @throws ClassCastException if elements of the specified collection |
226 |
+ |
* cannot be compared to one another according to the priority |
227 |
+ |
* queue's ordering. |
228 |
+ |
* @throws NullPointerException if <tt>c</tt> or any element within it |
229 |
+ |
* is <tt>null</tt> |
230 |
+ |
*/ |
231 |
+ |
public PriorityQueue(SortedSet<? extends E> c) { |
232 |
+ |
initializeArray(c); |
233 |
+ |
comparator = (Comparator<? super E>)c.comparator(); |
234 |
+ |
fillFromSorted(c); |
235 |
+ |
} |
236 |
+ |
|
237 |
+ |
/** |
238 |
+ |
* Resize array, if necessary, to be able to hold given index |
239 |
+ |
*/ |
240 |
+ |
private void grow(int index) { |
241 |
+ |
int newlen = queue.length; |
242 |
+ |
if (index < newlen) // don't need to grow |
243 |
+ |
return; |
244 |
+ |
if (index == Integer.MAX_VALUE) |
245 |
+ |
throw new OutOfMemoryError(); |
246 |
+ |
while (newlen <= index) { |
247 |
+ |
if (newlen >= Integer.MAX_VALUE / 2) // avoid overflow |
248 |
+ |
newlen = Integer.MAX_VALUE; |
249 |
+ |
else |
250 |
+ |
newlen <<= 2; |
251 |
+ |
} |
252 |
+ |
Object[] newQueue = new Object[newlen]; |
253 |
+ |
System.arraycopy(queue, 0, newQueue, 0, queue.length); |
254 |
+ |
queue = newQueue; |
255 |
+ |
} |
256 |
+ |
|
257 |
|
// Queue Methods |
258 |
|
|
259 |
|
/** |
260 |
< |
* Remove and return the minimal element from this priority queue |
147 |
< |
* if it contains one or more elements, otherwise return |
148 |
< |
* <tt>null</tt>. The term <i>minimal</i> is defined according to |
149 |
< |
* this priority queue's order. |
260 |
> |
* Add the specified element to this priority queue. |
261 |
|
* |
262 |
< |
* @return the minimal element from this priority queue if it contains |
263 |
< |
* one or more elements, otherwise <tt>null</tt>. |
262 |
> |
* @return <tt>true</tt> |
263 |
> |
* @throws ClassCastException if the specified element cannot be compared |
264 |
> |
* with elements currently in the priority queue according |
265 |
> |
* to the priority queue's ordering. |
266 |
> |
* @throws NullPointerException if the specified element is <tt>null</tt>. |
267 |
|
*/ |
268 |
+ |
public boolean offer(E o) { |
269 |
+ |
if (o == null) |
270 |
+ |
throw new NullPointerException(); |
271 |
+ |
modCount++; |
272 |
+ |
++size; |
273 |
+ |
|
274 |
+ |
// Grow backing store if necessary |
275 |
+ |
if (size >= queue.length) |
276 |
+ |
grow(size); |
277 |
+ |
|
278 |
+ |
queue[size] = o; |
279 |
+ |
fixUp(size); |
280 |
+ |
return true; |
281 |
+ |
} |
282 |
+ |
|
283 |
|
public E poll() { |
284 |
|
if (size == 0) |
285 |
|
return null; |
286 |
< |
return remove(1); |
286 |
> |
return (E) remove(1); |
287 |
|
} |
288 |
|
|
160 |
– |
/** |
161 |
– |
* Return, but do not remove, the minimal element from the |
162 |
– |
* priority queue, or return <tt>null</tt> if the queue is empty. |
163 |
– |
* The term <i>minimal</i> is defined according to this priority |
164 |
– |
* queue's order. This method returns the same object reference |
165 |
– |
* that would be returned by by the <tt>poll</tt> method. The two |
166 |
– |
* methods differ in that this method does not remove the element |
167 |
– |
* from the priority queue. |
168 |
– |
* |
169 |
– |
* @return the minimal element from this priority queue if it contains |
170 |
– |
* one or more elements, otherwise <tt>null</tt>. |
171 |
– |
*/ |
289 |
|
public E peek() { |
290 |
< |
return queue[1]; |
290 |
> |
return (E) queue[1]; |
291 |
|
} |
292 |
|
|
293 |
|
// Collection Methods |
294 |
|
|
295 |
+ |
// these first two override just to get the throws docs |
296 |
+ |
|
297 |
|
/** |
298 |
< |
* Removes a single instance of the specified element from this priority |
180 |
< |
* queue, if it is present. Returns true if this collection contained the |
181 |
< |
* specified element (or equivalently, if this collection changed as a |
182 |
< |
* result of the call). |
183 |
< |
* |
184 |
< |
* @param element the element to be removed from this collection, |
185 |
< |
* if present. |
186 |
< |
* @return <tt>true</tt> if this collection changed as a result of the |
187 |
< |
* call |
298 |
> |
* @throws NullPointerException if the specified element is <tt>null</tt>. |
299 |
|
* @throws ClassCastException if the specified element cannot be compared |
300 |
< |
* with elements currently in the priority queue according |
301 |
< |
* to the priority queue's ordering. |
191 |
< |
* @throws NullPointerException if the specified element is null. |
300 |
> |
* with elements currently in the priority queue according |
301 |
> |
* to the priority queue's ordering. |
302 |
|
*/ |
303 |
< |
public boolean remove(Object element) { |
304 |
< |
if (element == null) |
305 |
< |
throw new NullPointerException(); |
303 |
> |
public boolean add(E o) { |
304 |
> |
return super.add(o); |
305 |
> |
} |
306 |
> |
|
307 |
> |
/** |
308 |
> |
* @throws ClassCastException if any element cannot be compared |
309 |
> |
* with elements currently in the priority queue according |
310 |
> |
* to the priority queue's ordering. |
311 |
> |
* @throws NullPointerException if <tt>c</tt> or any element in <tt>c</tt> |
312 |
> |
* is <tt>null</tt> |
313 |
> |
*/ |
314 |
> |
public boolean addAll(Collection<? extends E> c) { |
315 |
> |
return super.addAll(c); |
316 |
> |
} |
317 |
> |
|
318 |
> |
public boolean remove(Object o) { |
319 |
> |
if (o == null) |
320 |
> |
return false; |
321 |
|
|
322 |
|
if (comparator == null) { |
323 |
|
for (int i = 1; i <= size; i++) { |
324 |
< |
if (((Comparable)queue[i]).compareTo(element) == 0) { |
324 |
> |
if (((Comparable<E>)queue[i]).compareTo((E)o) == 0) { |
325 |
|
remove(i); |
326 |
|
return true; |
327 |
|
} |
328 |
|
} |
329 |
|
} else { |
330 |
|
for (int i = 1; i <= size; i++) { |
331 |
< |
if (comparator.compare(queue[i], (E) element) == 0) { |
331 |
> |
if (comparator.compare((E)queue[i], (E)o) == 0) { |
332 |
|
remove(i); |
333 |
|
return true; |
334 |
|
} |
337 |
|
return false; |
338 |
|
} |
339 |
|
|
215 |
– |
/** |
216 |
– |
* Returns an iterator over the elements in this priority queue. The |
217 |
– |
* elements of the priority queue will be returned by this iterator in the |
218 |
– |
* order specified by the queue, which is to say the order they would be |
219 |
– |
* returned by repeated calls to <tt>poll</tt>. |
220 |
– |
* |
221 |
– |
* @return an <tt>Iterator</tt> over the elements in this priority queue. |
222 |
– |
*/ |
340 |
|
public Iterator<E> iterator() { |
341 |
|
return new Itr(); |
342 |
|
} |
370 |
|
checkForComodification(); |
371 |
|
if (cursor > size) |
372 |
|
throw new NoSuchElementException(); |
373 |
< |
E result = queue[cursor]; |
373 |
> |
E result = (E) queue[cursor]; |
374 |
|
lastRet = cursor++; |
375 |
|
return result; |
376 |
|
} |
395 |
|
|
396 |
|
/** |
397 |
|
* Returns the number of elements in this priority queue. |
398 |
< |
* |
398 |
> |
* |
399 |
|
* @return the number of elements in this priority queue. |
400 |
|
*/ |
401 |
|
public int size() { |
403 |
|
} |
404 |
|
|
405 |
|
/** |
289 |
– |
* Add the specified element to this priority queue. |
290 |
– |
* |
291 |
– |
* @param element the element to add. |
292 |
– |
* @return true |
293 |
– |
* @throws ClassCastException if the specified element cannot be compared |
294 |
– |
* with elements currently in the priority queue according |
295 |
– |
* to the priority queue's ordering. |
296 |
– |
* @throws NullPointerException if the specified element is null. |
297 |
– |
*/ |
298 |
– |
public boolean offer(E element) { |
299 |
– |
if (element == null) |
300 |
– |
throw new NullPointerException(); |
301 |
– |
modCount++; |
302 |
– |
++size; |
303 |
– |
|
304 |
– |
// Grow backing store if necessary |
305 |
– |
while (size >= queue.length) { |
306 |
– |
E[] newQueue = new E[2 * queue.length]; |
307 |
– |
System.arraycopy(queue, 0, newQueue, 0, queue.length); |
308 |
– |
queue = newQueue; |
309 |
– |
} |
310 |
– |
|
311 |
– |
queue[size] = element; |
312 |
– |
fixUp(size); |
313 |
– |
return true; |
314 |
– |
} |
315 |
– |
|
316 |
– |
/** |
406 |
|
* Remove all elements from the priority queue. |
407 |
|
*/ |
408 |
|
public void clear() { |
426 |
|
assert i <= size; |
427 |
|
modCount++; |
428 |
|
|
429 |
< |
E result = queue[i]; |
429 |
> |
E result = (E) queue[i]; |
430 |
|
queue[i] = queue[size]; |
431 |
|
queue[size--] = null; // Drop extra ref to prevent memory leak |
432 |
|
if (i <= size) |
447 |
|
if (comparator == null) { |
448 |
|
while (k > 1) { |
449 |
|
int j = k >> 1; |
450 |
< |
if (((Comparable)queue[j]).compareTo(queue[k]) <= 0) |
450 |
> |
if (((Comparable<E>)queue[j]).compareTo((E)queue[k]) <= 0) |
451 |
|
break; |
452 |
< |
E tmp = queue[j]; queue[j] = queue[k]; queue[k] = tmp; |
452 |
> |
Object tmp = queue[j]; queue[j] = queue[k]; queue[k] = tmp; |
453 |
|
k = j; |
454 |
|
} |
455 |
|
} else { |
456 |
|
while (k > 1) { |
457 |
|
int j = k >> 1; |
458 |
< |
if (comparator.compare(queue[j], queue[k]) <= 0) |
458 |
> |
if (comparator.compare((E)queue[j], (E)queue[k]) <= 0) |
459 |
|
break; |
460 |
< |
E tmp = queue[j]; queue[j] = queue[k]; queue[k] = tmp; |
460 |
> |
Object tmp = queue[j]; queue[j] = queue[k]; queue[k] = tmp; |
461 |
|
k = j; |
462 |
|
} |
463 |
|
} |
476 |
|
int j; |
477 |
|
if (comparator == null) { |
478 |
|
while ((j = k << 1) <= size) { |
479 |
< |
if (j<size && ((Comparable)queue[j]).compareTo(queue[j+1]) > 0) |
479 |
> |
if (j<size && ((Comparable<E>)queue[j]).compareTo((E)queue[j+1]) > 0) |
480 |
|
j++; // j indexes smallest kid |
481 |
< |
if (((Comparable)queue[k]).compareTo(queue[j]) <= 0) |
481 |
> |
if (((Comparable<E>)queue[k]).compareTo((E)queue[j]) <= 0) |
482 |
|
break; |
483 |
< |
E tmp = queue[j]; queue[j] = queue[k]; queue[k] = tmp; |
483 |
> |
Object tmp = queue[j]; queue[j] = queue[k]; queue[k] = tmp; |
484 |
|
k = j; |
485 |
|
} |
486 |
|
} else { |
487 |
|
while ((j = k << 1) <= size) { |
488 |
< |
if (j < size && comparator.compare(queue[j], queue[j+1]) > 0) |
488 |
> |
if (j < size && comparator.compare((E)queue[j], (E)queue[j+1]) > 0) |
489 |
|
j++; // j indexes smallest kid |
490 |
< |
if (comparator.compare(queue[k], queue[j]) <= 0) |
490 |
> |
if (comparator.compare((E)queue[k], (E)queue[j]) <= 0) |
491 |
|
break; |
492 |
< |
E tmp = queue[j]; queue[j] = queue[k]; queue[k] = tmp; |
492 |
> |
Object tmp = queue[j]; queue[j] = queue[k]; queue[k] = tmp; |
493 |
|
k = j; |
494 |
|
} |
495 |
|
} |
496 |
|
} |
497 |
|
|
498 |
< |
/** |
410 |
< |
* Returns the comparator associated with this priority queue, or |
411 |
< |
* <tt>null</tt> if it uses its elements' natural ordering. |
412 |
< |
* |
413 |
< |
* @return the comparator associated with this priority queue, or |
414 |
< |
* <tt>null</tt> if it uses its elements' natural ordering. |
415 |
< |
*/ |
416 |
< |
public Comparator comparator() { |
498 |
> |
public Comparator<? super E> comparator() { |
499 |
|
return comparator; |
500 |
|
} |
501 |
|
|
508 |
|
* <tt>Object</tt>) in the proper order. |
509 |
|
* @param s the stream |
510 |
|
*/ |
511 |
< |
private synchronized void writeObject(java.io.ObjectOutputStream s) |
511 |
> |
private void writeObject(java.io.ObjectOutputStream s) |
512 |
|
throws java.io.IOException{ |
513 |
|
// Write out element count, and any hidden stuff |
514 |
|
s.defaultWriteObject(); |
526 |
|
* deserialize it). |
527 |
|
* @param s the stream |
528 |
|
*/ |
529 |
< |
private synchronized void readObject(java.io.ObjectInputStream s) |
529 |
> |
private void readObject(java.io.ObjectInputStream s) |
530 |
|
throws java.io.IOException, ClassNotFoundException { |
531 |
|
// Read in size, and any hidden stuff |
532 |
|
s.defaultReadObject(); |
533 |
|
|
534 |
|
// Read in array length and allocate array |
535 |
|
int arrayLength = s.readInt(); |
536 |
< |
queue = new E[arrayLength]; |
536 |
> |
queue = new Object[arrayLength]; |
537 |
|
|
538 |
|
// Read in all elements in the proper order. |
539 |
|
for (int i=0; i<size; i++) |
540 |
< |
queue[i] = (E)s.readObject(); |
540 |
> |
queue[i] = s.readObject(); |
541 |
|
} |
542 |
|
|
543 |
|
} |
544 |
+ |
|