| 56 |
|
* the priority queue in any particular order. If you need ordered |
| 57 |
|
* traversal, consider using {@code Arrays.sort(pq.toArray())}. |
| 58 |
|
* |
| 59 |
< |
* <p> <strong>Note that this implementation is not synchronized.</strong> |
| 59 |
> |
* <p><strong>Note that this implementation is not synchronized.</strong> |
| 60 |
|
* Multiple threads should not access a {@code PriorityQueue} |
| 61 |
|
* instance concurrently if any of the threads modifies the queue. |
| 62 |
|
* Instead, use the thread-safe {@link |
| 63 |
|
* java.util.concurrent.PriorityBlockingQueue} class. |
| 64 |
|
* |
| 65 |
|
* <p>Implementation note: this implementation provides |
| 66 |
< |
* O(log(n)) time for the enqueing and dequeing methods |
| 66 |
> |
* O(log(n)) time for the enqueuing and dequeuing methods |
| 67 |
|
* ({@code offer}, {@code poll}, {@code remove()} and {@code add}); |
| 68 |
|
* linear time for the {@code remove(Object)} and {@code contains(Object)} |
| 69 |
|
* methods; and constant time for the retrieval methods |
| 77 |
|
* @author Josh Bloch, Doug Lea |
| 78 |
|
* @param <E> the type of elements held in this collection |
| 79 |
|
*/ |
| 80 |
+ |
@SuppressWarnings("unchecked") |
| 81 |
|
public class PriorityQueue<E> extends AbstractQueue<E> |
| 82 |
|
implements java.io.Serializable { |
| 83 |
|
|
| 332 |
|
} |
| 333 |
|
|
| 334 |
|
public E peek() { |
| 335 |
< |
if (size == 0) |
| 335 |
< |
return null; |
| 336 |
< |
return (E) queue[0]; |
| 335 |
> |
return (size == 0) ? null : (E) queue[0]; |
| 336 |
|
} |
| 337 |
|
|
| 338 |
|
private int indexOf(Object o) { |
| 429 |
|
* precise control over the runtime type of the output array, and may, |
| 430 |
|
* under certain circumstances, be used to save allocation costs. |
| 431 |
|
* |
| 432 |
< |
* <p>Suppose <tt>x</tt> is a queue known to contain only strings. |
| 432 |
> |
* <p>Suppose {@code x} is a queue known to contain only strings. |
| 433 |
|
* The following code can be used to dump the queue into a newly |
| 434 |
< |
* allocated array of <tt>String</tt>: |
| 434 |
> |
* allocated array of {@code String}: |
| 435 |
|
* |
| 436 |
< |
* <pre> |
| 438 |
< |
* String[] y = x.toArray(new String[0]);</pre> |
| 436 |
> |
* <pre> {@code String[] y = x.toArray(new String[0]);}</pre> |
| 437 |
|
* |
| 438 |
< |
* Note that <tt>toArray(new Object[0])</tt> is identical in function to |
| 439 |
< |
* <tt>toArray()</tt>. |
| 438 |
> |
* Note that {@code toArray(new Object[0])} is identical in function to |
| 439 |
> |
* {@code toArray()}. |
| 440 |
|
* |
| 441 |
|
* @param a the array into which the elements of the queue are to |
| 442 |
|
* be stored, if it is big enough; otherwise, a new array of the |
| 590 |
|
* avoid missing traversing elements. |
| 591 |
|
*/ |
| 592 |
|
private E removeAt(int i) { |
| 593 |
< |
assert i >= 0 && i < size; |
| 593 |
> |
// assert i >= 0 && i < size; |
| 594 |
|
modCount++; |
| 595 |
|
int s = --size; |
| 596 |
|
if (s == i) // removed last element |
| 725 |
|
} |
| 726 |
|
|
| 727 |
|
/** |
| 728 |
< |
* Saves the state of the instance to a stream (that |
| 731 |
< |
* is, serializes it). |
| 728 |
> |
* Saves this queue to a stream (that is, serializes it). |
| 729 |
|
* |
| 730 |
|
* @serialData The length of the array backing the instance is |
| 731 |
|
* emitted (int), followed by all of its elements |
| 732 |
|
* (each an {@code Object}) in the proper order. |
| 736 |
– |
* @param s the stream |
| 733 |
|
*/ |
| 734 |
|
private void writeObject(java.io.ObjectOutputStream s) |
| 735 |
< |
throws java.io.IOException{ |
| 735 |
> |
throws java.io.IOException { |
| 736 |
|
// Write out element count, and any hidden stuff |
| 737 |
|
s.defaultWriteObject(); |
| 738 |
|
|
| 745 |
|
} |
| 746 |
|
|
| 747 |
|
/** |
| 748 |
< |
* Reconstitutes the {@code PriorityQueue} instance from a stream |
| 753 |
< |
* (that is, deserializes it). |
| 754 |
< |
* |
| 755 |
< |
* @param s the stream |
| 748 |
> |
* Reconstitutes this queue from a stream (that is, deserializes it). |
| 749 |
|
*/ |
| 750 |
|
private void readObject(java.io.ObjectInputStream s) |
| 751 |
|
throws java.io.IOException, ClassNotFoundException { |
