| 1 |
< |
package java.util; |
| 1 |
> |
/* |
| 2 |
> |
* %W% %E% |
| 3 |
> |
* |
| 4 |
> |
* Copyright 2003 Sun Microsystems, Inc. All rights reserved. |
| 5 |
> |
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. |
| 6 |
> |
*/ |
| 7 |
> |
|
| 8 |
> |
package java.util; |
| 9 |
|
|
| 10 |
|
/** |
| 11 |
< |
* An unbounded priority {@linkplain Queue queue} based on a priority heap. |
| 12 |
< |
* This queue orders |
| 13 |
< |
* elements according to an order specified at construction time, which is |
| 14 |
< |
* specified in the same manner as {@link java.util.TreeSet} and |
| 15 |
< |
* {@link java.util.TreeMap}: elements are ordered |
| 16 |
< |
* either according to their <i>natural order</i> (see {@link Comparable}), or |
| 17 |
< |
* according to a {@link java.util.Comparator}, depending on which |
| 18 |
< |
* constructor is used. |
| 19 |
< |
* <p>The <em>head</em> of this queue is the <em>least</em> element with |
| 20 |
< |
* respect to the specified ordering. |
| 21 |
< |
* If multiple elements are tied for least value, the |
| 22 |
< |
* head is one of those elements. A priority queue does not permit |
| 23 |
< |
* <tt>null</tt> elements. |
| 11 |
> |
* An unbounded priority {@linkplain Queue queue} based on a priority |
| 12 |
> |
* heap. This queue orders elements according to an order specified |
| 13 |
> |
* at construction time, which is specified either according to their |
| 14 |
> |
* <i>natural order</i> (see {@link Comparable}), or according to a |
| 15 |
> |
* {@link java.util.Comparator}, depending on which constructor is |
| 16 |
> |
* used. A priority queue does not permit <tt>null</tt> elements. |
| 17 |
> |
* A priority queue relying on natural ordering also does not |
| 18 |
> |
* permit insertion of non-comparable objects (doing so may result |
| 19 |
> |
* in <tt>ClassCastException</tt>). |
| 20 |
> |
* |
| 21 |
> |
* <p>The <em>head</em> of this queue is the <em>least</em> element |
| 22 |
> |
* with respect to the specified ordering. If multiple elements are |
| 23 |
> |
* tied for least value, the head is one of those elements -- ties are |
| 24 |
> |
* broken arbitrarily. The queue retrieval operations <tt>poll</tt>, |
| 25 |
> |
* <tt>remove</tt>, <tt>peek</tt>, and <tt>element</tt> access the |
| 26 |
> |
* element at the head of the queue. |
| 27 |
|
* |
| 28 |
< |
* <p>The {@link #remove()} and {@link #poll()} methods remove and |
| 29 |
< |
* return the head of the queue. |
| 28 |
> |
* <p>A priority queue is unbounded, but has an internal |
| 29 |
> |
* <i>capacity</i> governing the size of an array used to store the |
| 30 |
> |
* elements on the queue. It is always at least as large as the queue |
| 31 |
> |
* size. As elements are added to a priority queue, its capacity |
| 32 |
> |
* grows automatically. The details of the growth policy are not |
| 33 |
> |
* specified. |
| 34 |
|
* |
| 35 |
< |
* <p>The {@link #element()} and {@link #peek()} methods return, but do |
| 36 |
< |
* not delete, the head of the queue. |
| 35 |
> |
* <p>This class implements all of the <em>optional</em> methods of |
| 36 |
> |
* the {@link Collection} and {@link Iterator} interfaces. The |
| 37 |
> |
* Iterator provided in method {@link #iterator()} is <em>not</em> |
| 38 |
> |
* guaranteed to traverse the elements of the PriorityQueue in any |
| 39 |
> |
* particular order. If you need ordered traversal, consider using |
| 40 |
> |
* <tt>Arrays.sort(pq.toArray())</tt>. |
| 41 |
|
* |
| 42 |
< |
* <p>A priority queue has a <i>capacity</i>. The capacity is the |
| 43 |
< |
* size of the array used internally to store the elements on the |
| 44 |
< |
* queue. |
| 45 |
< |
* It is always at least as large as the queue size. As |
| 46 |
< |
* elements are added to a priority queue, its capacity grows |
| 29 |
< |
* automatically. The details of the growth policy are not specified. |
| 42 |
> |
* <p> <strong>Note that this implementation is not synchronized.</strong> |
| 43 |
> |
* Multiple threads should not access a <tt>PriorityQueue</tt> |
| 44 |
> |
* instance concurrently if any of the threads modifies the list |
| 45 |
> |
* structurally. Instead, use the thread-safe {@link |
| 46 |
> |
* java.util.concurrent.PriorityBlockingQueue} class. |
| 47 |
|
* |
| 48 |
+ |
* |
| 49 |
|
* <p>Implementation note: this implementation provides O(log(n)) time |
| 50 |
|
* for the insertion methods (<tt>offer</tt>, <tt>poll</tt>, |
| 51 |
|
* <tt>remove()</tt> and <tt>add</tt>) methods; linear time for the |
| 57 |
|
* <a href="{@docRoot}/../guide/collections/index.html"> |
| 58 |
|
* Java Collections Framework</a>. |
| 59 |
|
* @since 1.5 |
| 60 |
+ |
* @version %I%, %G% |
| 61 |
|
* @author Josh Bloch |
| 62 |
+ |
* @param <E> the type of elements held in this collection |
| 63 |
|
*/ |
| 64 |
|
public class PriorityQueue<E> extends AbstractQueue<E> |
| 65 |
|
implements Queue<E>, java.io.Serializable { |
| 66 |
|
|
| 67 |
+ |
private static final long serialVersionUID = -7720805057305804111L; |
| 68 |
+ |
|
| 69 |
|
private static final int DEFAULT_INITIAL_CAPACITY = 11; |
| 70 |
|
|
| 71 |
|
/** |
| 103 |
|
/** |
| 104 |
|
* Creates a <tt>PriorityQueue</tt> with the default initial capacity |
| 105 |
|
* (11) that orders its elements according to their natural |
| 106 |
< |
* ordering (using <tt>Comparable</tt>.) |
| 106 |
> |
* ordering (using <tt>Comparable</tt>). |
| 107 |
|
*/ |
| 108 |
|
public PriorityQueue() { |
| 109 |
|
this(DEFAULT_INITIAL_CAPACITY, null); |
| 112 |
|
/** |
| 113 |
|
* Creates a <tt>PriorityQueue</tt> with the specified initial capacity |
| 114 |
|
* that orders its elements according to their natural ordering |
| 115 |
< |
* (using <tt>Comparable</tt>.) |
| 115 |
> |
* (using <tt>Comparable</tt>). |
| 116 |
|
* |
| 117 |
|
* @param initialCapacity the initial capacity for this priority queue. |
| 118 |
|
* @throws IllegalArgumentException if <tt>initialCapacity</tt> is less |
| 158 |
|
/** |
| 159 |
|
* Initially fill elements of the queue array under the |
| 160 |
|
* knowledge that it is sorted or is another PQ, in which |
| 161 |
< |
* case we can just place the elements without fixups. |
| 161 |
> |
* case we can just place the elements in the order presented. |
| 162 |
|
*/ |
| 163 |
|
private void fillFromSorted(Collection<? extends E> c) { |
| 164 |
|
for (Iterator<? extends E> i = c.iterator(); i.hasNext(); ) |
| 165 |
|
queue[++size] = i.next(); |
| 166 |
|
} |
| 167 |
|
|
| 146 |
– |
|
| 168 |
|
/** |
| 169 |
< |
* Initially fill elements of the queue array that is |
| 170 |
< |
* not to our knowledge sorted, so we must add them |
| 171 |
< |
* one by one. |
| 169 |
> |
* Initially fill elements of the queue array that is not to our knowledge |
| 170 |
> |
* sorted, so we must rearrange the elements to guarantee the heap |
| 171 |
> |
* invariant. |
| 172 |
|
*/ |
| 173 |
|
private void fillFromUnsorted(Collection<? extends E> c) { |
| 174 |
|
for (Iterator<? extends E> i = c.iterator(); i.hasNext(); ) |
| 175 |
< |
add(i.next()); |
| 175 |
> |
queue[++size] = i.next(); |
| 176 |
> |
heapify(); |
| 177 |
|
} |
| 178 |
|
|
| 179 |
|
/** |
| 181 |
|
* specified collection. The priority queue has an initial |
| 182 |
|
* capacity of 110% of the size of the specified collection or 1 |
| 183 |
|
* if the collection is empty. If the specified collection is an |
| 184 |
< |
* instance of a {@link SortedSet} or is another |
| 184 |
> |
* instance of a {@link java.util.SortedSet} or is another |
| 185 |
|
* <tt>PriorityQueue</tt>, the priority queue will be sorted |
| 186 |
|
* according to the same comparator, or according to its elements' |
| 187 |
|
* natural order if the collection is sorted according to its |
| 198 |
|
*/ |
| 199 |
|
public PriorityQueue(Collection<? extends E> c) { |
| 200 |
|
initializeArray(c); |
| 201 |
< |
if (c instanceof SortedSet<? extends E>) { |
| 202 |
< |
SortedSet<? extends E> s = (SortedSet<? extends E>) c; |
| 201 |
> |
if (c instanceof SortedSet) { |
| 202 |
> |
// @fixme double-cast workaround for compiler |
| 203 |
> |
SortedSet<? extends E> s = (SortedSet<? extends E>) (SortedSet)c; |
| 204 |
|
comparator = (Comparator<? super E>)s.comparator(); |
| 205 |
|
fillFromSorted(s); |
| 206 |
< |
} |
| 184 |
< |
else if (c instanceof PriorityQueue<? extends E>) { |
| 206 |
> |
} else if (c instanceof PriorityQueue) { |
| 207 |
|
PriorityQueue<? extends E> s = (PriorityQueue<? extends E>) c; |
| 208 |
|
comparator = (Comparator<? super E>)s.comparator(); |
| 209 |
|
fillFromSorted(s); |
| 210 |
< |
} |
| 189 |
< |
else { |
| 210 |
> |
} else { |
| 211 |
|
comparator = null; |
| 212 |
|
fillFromUnsorted(c); |
| 213 |
|
} |
| 279 |
|
queue = newQueue; |
| 280 |
|
} |
| 281 |
|
|
| 261 |
– |
// Queue Methods |
| 262 |
– |
|
| 263 |
– |
|
| 282 |
|
|
| 283 |
|
/** |
| 284 |
< |
* Add the specified element to this priority queue. |
| 284 |
> |
* Inserts the specified element into this priority queue. |
| 285 |
|
* |
| 286 |
|
* @return <tt>true</tt> |
| 287 |
|
* @throws ClassCastException if the specified element cannot be compared |
| 304 |
|
return true; |
| 305 |
|
} |
| 306 |
|
|
| 307 |
< |
public E poll() { |
| 307 |
> |
public E peek() { |
| 308 |
|
if (size == 0) |
| 309 |
|
return null; |
| 292 |
– |
return (E) remove(1); |
| 293 |
– |
} |
| 294 |
– |
|
| 295 |
– |
public E peek() { |
| 310 |
|
return (E) queue[1]; |
| 311 |
|
} |
| 312 |
|
|
| 317 |
|
* @return <tt>true</tt> (as per the general contract of |
| 318 |
|
* <tt>Collection.add</tt>). |
| 319 |
|
* |
| 320 |
< |
* @throws NullPointerException {@inheritDoc} |
| 320 |
> |
* @throws NullPointerException if the specified element is <tt>null</tt>. |
| 321 |
|
* @throws ClassCastException if the specified element cannot be compared |
| 322 |
|
* with elements currently in the priority queue according |
| 323 |
|
* to the priority queue's ordering. |
| 324 |
|
*/ |
| 325 |
|
public boolean add(E o) { |
| 326 |
< |
return super.add(o); |
| 313 |
< |
} |
| 314 |
< |
|
| 315 |
< |
|
| 316 |
< |
/** |
| 317 |
< |
* Adds all of the elements in the specified collection to this queue. |
| 318 |
< |
* The behavior of this operation is undefined if |
| 319 |
< |
* the specified collection is modified while the operation is in |
| 320 |
< |
* progress. (This implies that the behavior of this call is undefined if |
| 321 |
< |
* the specified collection is this queue, and this queue is nonempty.) |
| 322 |
< |
* <p> |
| 323 |
< |
* This implementation iterates over the specified collection, and adds |
| 324 |
< |
* each object returned by the iterator to this collection, in turn. |
| 325 |
< |
* @throws NullPointerException {@inheritDoc} |
| 326 |
< |
* @throws ClassCastException if any element cannot be compared |
| 327 |
< |
* with elements currently in the priority queue according |
| 328 |
< |
* to the priority queue's ordering. |
| 329 |
< |
*/ |
| 330 |
< |
public boolean addAll(Collection<? extends E> c) { |
| 331 |
< |
return super.addAll(c); |
| 326 |
> |
return offer(o); |
| 327 |
|
} |
| 328 |
|
|
| 334 |
– |
|
| 335 |
– |
/** |
| 336 |
– |
* Removes a single instance of the specified element from this |
| 337 |
– |
* queue, if it is present. More formally, |
| 338 |
– |
* removes an element <tt>e</tt> such that <tt>(o==null ? e==null : |
| 339 |
– |
* o.equals(e))</tt>, if the queue contains one or more such |
| 340 |
– |
* elements. Returns <tt>true</tt> if the queue contained the |
| 341 |
– |
* specified element (or equivalently, if the queue changed as a |
| 342 |
– |
* result of the call). |
| 343 |
– |
* |
| 344 |
– |
* <p>This implementation iterates over the queue looking for the |
| 345 |
– |
* specified element. If it finds the element, it removes the element |
| 346 |
– |
* from the queue using the iterator's remove method.<p> |
| 347 |
– |
* |
| 348 |
– |
*/ |
| 329 |
|
public boolean remove(Object o) { |
| 330 |
|
if (o == null) |
| 331 |
|
return false; |
| 333 |
|
if (comparator == null) { |
| 334 |
|
for (int i = 1; i <= size; i++) { |
| 335 |
|
if (((Comparable<E>)queue[i]).compareTo((E)o) == 0) { |
| 336 |
< |
remove(i); |
| 336 |
> |
removeAt(i); |
| 337 |
|
return true; |
| 338 |
|
} |
| 339 |
|
} |
| 340 |
|
} else { |
| 341 |
|
for (int i = 1; i <= size; i++) { |
| 342 |
|
if (comparator.compare((E)queue[i], (E)o) == 0) { |
| 343 |
< |
remove(i); |
| 343 |
> |
removeAt(i); |
| 344 |
|
return true; |
| 345 |
|
} |
| 346 |
|
} |
| 359 |
|
} |
| 360 |
|
|
| 361 |
|
private class Itr implements Iterator<E> { |
| 362 |
+ |
|
| 363 |
|
/** |
| 364 |
|
* Index (into queue array) of element to be returned by |
| 365 |
|
* subsequent call to next. |
| 367 |
|
private int cursor = 1; |
| 368 |
|
|
| 369 |
|
/** |
| 370 |
< |
* Index of element returned by most recent call to next or |
| 371 |
< |
* previous. Reset to 0 if this element is deleted by a call |
| 372 |
< |
* to remove. |
| 370 |
> |
* Index of element returned by most recent call to next, |
| 371 |
> |
* unless that element came from the forgetMeNot list. |
| 372 |
> |
* Reset to 0 if element is deleted by a call to remove. |
| 373 |
|
*/ |
| 374 |
|
private int lastRet = 0; |
| 375 |
|
|
| 380 |
|
*/ |
| 381 |
|
private int expectedModCount = modCount; |
| 382 |
|
|
| 383 |
+ |
/** |
| 384 |
+ |
* A list of elements that were moved from the unvisited portion of |
| 385 |
+ |
* the heap into the visited portion as a result of "unlucky" element |
| 386 |
+ |
* removals during the iteration. (Unlucky element removals are those |
| 387 |
+ |
* that require a fixup instead of a fixdown.) We must visit all of |
| 388 |
+ |
* the elements in this list to complete the iteration. We do this |
| 389 |
+ |
* after we've completed the "normal" iteration. |
| 390 |
+ |
* |
| 391 |
+ |
* We expect that most iterations, even those involving removals, |
| 392 |
+ |
* will not use need to store elements in this field. |
| 393 |
+ |
*/ |
| 394 |
+ |
private ArrayList<E> forgetMeNot = null; |
| 395 |
+ |
|
| 396 |
+ |
/** |
| 397 |
+ |
* Element returned by the most recent call to next iff that |
| 398 |
+ |
* element was drawn from the forgetMeNot list. |
| 399 |
+ |
*/ |
| 400 |
+ |
private Object lastRetElt = null; |
| 401 |
+ |
|
| 402 |
|
public boolean hasNext() { |
| 403 |
< |
return cursor <= size; |
| 403 |
> |
return cursor <= size || forgetMeNot != null; |
| 404 |
|
} |
| 405 |
|
|
| 406 |
|
public E next() { |
| 407 |
|
checkForComodification(); |
| 408 |
< |
if (cursor > size) |
| 408 |
> |
E result; |
| 409 |
> |
if (cursor <= size) { |
| 410 |
> |
result = (E) queue[cursor]; |
| 411 |
> |
lastRet = cursor++; |
| 412 |
> |
} |
| 413 |
> |
else if (forgetMeNot == null) |
| 414 |
|
throw new NoSuchElementException(); |
| 415 |
< |
E result = (E) queue[cursor]; |
| 416 |
< |
lastRet = cursor++; |
| 415 |
> |
else { |
| 416 |
> |
int remaining = forgetMeNot.size(); |
| 417 |
> |
result = forgetMeNot.remove(remaining - 1); |
| 418 |
> |
if (remaining == 1) |
| 419 |
> |
forgetMeNot = null; |
| 420 |
> |
lastRet = 0; |
| 421 |
> |
lastRetElt = result; |
| 422 |
> |
} |
| 423 |
|
return result; |
| 424 |
|
} |
| 425 |
|
|
| 426 |
|
public void remove() { |
| 416 |
– |
if (lastRet == 0) |
| 417 |
– |
throw new IllegalStateException(); |
| 427 |
|
checkForComodification(); |
| 428 |
|
|
| 429 |
< |
PriorityQueue.this.remove(lastRet); |
| 430 |
< |
if (lastRet < cursor) |
| 431 |
< |
cursor--; |
| 432 |
< |
lastRet = 0; |
| 429 |
> |
if (lastRet != 0) { |
| 430 |
> |
E moved = PriorityQueue.this.removeAt(lastRet); |
| 431 |
> |
lastRet = 0; |
| 432 |
> |
if (moved == null) { |
| 433 |
> |
cursor--; |
| 434 |
> |
} else { |
| 435 |
> |
if (forgetMeNot == null) |
| 436 |
> |
forgetMeNot = new ArrayList<E>(); |
| 437 |
> |
forgetMeNot.add(moved); |
| 438 |
> |
} |
| 439 |
> |
} else if (lastRetElt != null) { |
| 440 |
> |
PriorityQueue.this.remove(lastRetElt); |
| 441 |
> |
lastRetElt = null; |
| 442 |
> |
} else { |
| 443 |
> |
throw new IllegalStateException(); |
| 444 |
> |
} |
| 445 |
> |
|
| 446 |
|
expectedModCount = modCount; |
| 447 |
|
} |
| 448 |
|
|
| 469 |
|
size = 0; |
| 470 |
|
} |
| 471 |
|
|
| 472 |
+ |
public E poll() { |
| 473 |
+ |
if (size == 0) |
| 474 |
+ |
return null; |
| 475 |
+ |
modCount++; |
| 476 |
+ |
|
| 477 |
+ |
E result = (E) queue[1]; |
| 478 |
+ |
queue[1] = queue[size]; |
| 479 |
+ |
queue[size--] = null; // Drop extra ref to prevent memory leak |
| 480 |
+ |
if (size > 1) |
| 481 |
+ |
fixDown(1); |
| 482 |
+ |
|
| 483 |
+ |
return result; |
| 484 |
+ |
} |
| 485 |
+ |
|
| 486 |
|
/** |
| 487 |
< |
* Removes and returns the ith element from queue. Recall |
| 488 |
< |
* that queue is one-based, so 1 <= i <= size. |
| 487 |
> |
* Removes and returns the ith element from queue. (Recall that queue |
| 488 |
> |
* is one-based, so 1 <= i <= size.) |
| 489 |
|
* |
| 490 |
< |
* XXX: Could further special-case i==size, but is it worth it? |
| 491 |
< |
* XXX: Could special-case i==0, but is it worth it? |
| 490 |
> |
* Normally this method leaves the elements at positions from 1 up to i-1, |
| 491 |
> |
* inclusive, untouched. Under these circumstances, it returns null. |
| 492 |
> |
* Occasionally, in order to maintain the heap invariant, it must move |
| 493 |
> |
* the last element of the list to some index in the range [2, i-1], |
| 494 |
> |
* and move the element previously at position (i/2) to position i. |
| 495 |
> |
* Under these circumstances, this method returns the element that was |
| 496 |
> |
* previously at the end of the list and is now at some position between |
| 497 |
> |
* 2 and i-1 inclusive. |
| 498 |
|
*/ |
| 499 |
< |
private E remove(int i) { |
| 500 |
< |
assert i <= size; |
| 499 |
> |
private E removeAt(int i) { |
| 500 |
> |
assert i > 0 && i <= size; |
| 501 |
|
modCount++; |
| 502 |
|
|
| 503 |
< |
E result = (E) queue[i]; |
| 504 |
< |
queue[i] = queue[size]; |
| 503 |
> |
E moved = (E) queue[size]; |
| 504 |
> |
queue[i] = moved; |
| 505 |
|
queue[size--] = null; // Drop extra ref to prevent memory leak |
| 506 |
< |
if (i <= size) |
| 506 |
> |
if (i <= size) { |
| 507 |
|
fixDown(i); |
| 508 |
< |
return result; |
| 508 |
> |
if (queue[i] == moved) { |
| 509 |
> |
fixUp(i); |
| 510 |
> |
if (queue[i] != moved) |
| 511 |
> |
return moved; |
| 512 |
> |
} |
| 513 |
> |
} |
| 514 |
> |
return null; |
| 515 |
|
} |
| 516 |
|
|
| 517 |
|
/** |
| 534 |
|
} |
| 535 |
|
} else { |
| 536 |
|
while (k > 1) { |
| 537 |
< |
int j = k >> 1; |
| 537 |
> |
int j = k >>> 1; |
| 538 |
|
if (comparator.compare((E)queue[j], (E)queue[k]) <= 0) |
| 539 |
|
break; |
| 540 |
|
Object tmp = queue[j]; queue[j] = queue[k]; queue[k] = tmp; |
| 555 |
|
private void fixDown(int k) { |
| 556 |
|
int j; |
| 557 |
|
if (comparator == null) { |
| 558 |
< |
while ((j = k << 1) <= size) { |
| 559 |
< |
if (j<size && ((Comparable<E>)queue[j]).compareTo((E)queue[j+1]) > 0) |
| 558 |
> |
while ((j = k << 1) <= size && (j > 0)) { |
| 559 |
> |
if (j<size && |
| 560 |
> |
((Comparable<E>)queue[j]).compareTo((E)queue[j+1]) > 0) |
| 561 |
|
j++; // j indexes smallest kid |
| 562 |
+ |
|
| 563 |
|
if (((Comparable<E>)queue[k]).compareTo((E)queue[j]) <= 0) |
| 564 |
|
break; |
| 565 |
|
Object tmp = queue[j]; queue[j] = queue[k]; queue[k] = tmp; |
| 566 |
|
k = j; |
| 567 |
|
} |
| 568 |
|
} else { |
| 569 |
< |
while ((j = k << 1) <= size) { |
| 570 |
< |
if (j < size && comparator.compare((E)queue[j], (E)queue[j+1]) > 0) |
| 569 |
> |
while ((j = k << 1) <= size && (j > 0)) { |
| 570 |
> |
if (j<size && |
| 571 |
> |
comparator.compare((E)queue[j], (E)queue[j+1]) > 0) |
| 572 |
|
j++; // j indexes smallest kid |
| 573 |
|
if (comparator.compare((E)queue[k], (E)queue[j]) <= 0) |
| 574 |
|
break; |
| 578 |
|
} |
| 579 |
|
} |
| 580 |
|
|
| 581 |
+ |
/** |
| 582 |
+ |
* Establishes the heap invariant (described above) in the entire tree, |
| 583 |
+ |
* assuming nothing about the order of the elements prior to the call. |
| 584 |
+ |
*/ |
| 585 |
+ |
private void heapify() { |
| 586 |
+ |
for (int i = size/2; i >= 1; i--) |
| 587 |
+ |
fixDown(i); |
| 588 |
+ |
} |
| 589 |
|
|
| 590 |
|
/** |
| 591 |
|
* Returns the comparator used to order this collection, or <tt>null</tt> |
| 592 |
|
* if this collection is sorted according to its elements natural ordering |
| 593 |
< |
* (using <tt>Comparable</tt>.) |
| 593 |
> |
* (using <tt>Comparable</tt>). |
| 594 |
|
* |
| 595 |
|
* @return the comparator used to order this collection, or <tt>null</tt> |
| 596 |
|
* if this collection is sorted according to its elements natural ordering. |
| 617 |
|
s.writeInt(queue.length); |
| 618 |
|
|
| 619 |
|
// Write out all elements in the proper order. |
| 620 |
< |
for (int i=0; i<size; i++) |
| 620 |
> |
for (int i=1; i<=size; i++) |
| 621 |
|
s.writeObject(queue[i]); |
| 622 |
|
} |
| 623 |
|
|
| 636 |
|
queue = new Object[arrayLength]; |
| 637 |
|
|
| 638 |
|
// Read in all elements in the proper order. |
| 639 |
< |
for (int i=0; i<size; i++) |
| 640 |
< |
queue[i] = s.readObject(); |
| 639 |
> |
for (int i=1; i<=size; i++) |
| 640 |
> |
queue[i] = (E) s.readObject(); |
| 641 |
|
} |
| 642 |
|
|
| 643 |
|
} |
| 585 |
– |
|
