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/* |
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* Written by Doug Lea with assistance from members of JCP JSR-166 |
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* Expert Group and released to the public domain, as explained at |
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* http://creativecommons.org/publicdomain/zero/1.0/ |
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* Other contributors include Andrew Wright, Jeffrey Hayes, |
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* Pat Fisher, Mike Judd. |
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*/ |
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|
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import java.util.Arrays; |
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import java.util.Collection; |
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import java.util.Comparator; |
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import java.util.Iterator; |
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import java.util.NoSuchElementException; |
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import java.util.PriorityQueue; |
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import java.util.Queue; |
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|
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import junit.framework.Test; |
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import junit.framework.TestSuite; |
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|
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public class PriorityQueueTest extends JSR166TestCase { |
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public static void main(String[] args) { |
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main(suite(), args); |
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} |
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public static Test suite() { |
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return new TestSuite(PriorityQueueTest.class); |
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} |
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|
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static class MyReverseComparator implements Comparator { |
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public int compare(Object x, Object y) { |
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return ((Comparable)y).compareTo(x); |
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} |
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} |
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|
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/** |
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* Returns a new queue of given size containing consecutive |
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* Integers 0 ... n - 1. |
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*/ |
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private PriorityQueue<Integer> populatedQueue(int n) { |
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PriorityQueue<Integer> q = new PriorityQueue<Integer>(n); |
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assertTrue(q.isEmpty()); |
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for (int i = n - 1; i >= 0; i -= 2) |
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assertTrue(q.offer(new Integer(i))); |
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for (int i = (n & 1); i < n; i += 2) |
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assertTrue(q.offer(new Integer(i))); |
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assertFalse(q.isEmpty()); |
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assertEquals(n, q.size()); |
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assertEquals((Integer) 0, q.peek()); |
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return q; |
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} |
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|
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/** |
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* A new queue has unbounded capacity |
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*/ |
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public void testConstructor1() { |
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assertEquals(0, new PriorityQueue(SIZE).size()); |
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} |
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|
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/** |
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* Constructor throws IAE if capacity argument nonpositive |
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*/ |
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public void testConstructor2() { |
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try { |
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new PriorityQueue(0); |
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shouldThrow(); |
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} catch (IllegalArgumentException success) {} |
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} |
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|
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/** |
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* Initializing from null Collection throws NPE |
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*/ |
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public void testConstructor3() { |
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try { |
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new PriorityQueue((Collection)null); |
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shouldThrow(); |
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} catch (NullPointerException success) {} |
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} |
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|
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/** |
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* Initializing from Collection of null elements throws NPE |
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*/ |
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public void testConstructor4() { |
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try { |
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new PriorityQueue(Arrays.asList(new Integer[SIZE])); |
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shouldThrow(); |
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} catch (NullPointerException success) {} |
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} |
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|
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/** |
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* Initializing from Collection with some null elements throws NPE |
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*/ |
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public void testConstructor5() { |
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Integer[] ints = new Integer[SIZE]; |
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for (int i = 0; i < SIZE - 1; ++i) |
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ints[i] = new Integer(i); |
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try { |
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new PriorityQueue(Arrays.asList(ints)); |
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shouldThrow(); |
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} catch (NullPointerException success) {} |
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} |
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|
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/** |
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* Queue contains all elements of collection used to initialize |
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*/ |
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public void testConstructor6() { |
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Integer[] ints = new Integer[SIZE]; |
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for (int i = 0; i < SIZE; ++i) |
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ints[i] = new Integer(i); |
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PriorityQueue q = new PriorityQueue(Arrays.asList(ints)); |
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for (int i = 0; i < SIZE; ++i) |
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assertEquals(ints[i], q.poll()); |
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} |
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|
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/** |
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* The comparator used in constructor is used |
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*/ |
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public void testConstructor7() { |
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MyReverseComparator cmp = new MyReverseComparator(); |
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PriorityQueue q = new PriorityQueue(SIZE, cmp); |
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assertEquals(cmp, q.comparator()); |
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Integer[] ints = new Integer[SIZE]; |
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for (int i = 0; i < SIZE; ++i) |
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ints[i] = new Integer(i); |
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q.addAll(Arrays.asList(ints)); |
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for (int i = SIZE - 1; i >= 0; --i) |
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assertEquals(ints[i], q.poll()); |
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} |
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|
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/** |
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* isEmpty is true before add, false after |
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*/ |
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public void testEmpty() { |
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PriorityQueue q = new PriorityQueue(2); |
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assertTrue(q.isEmpty()); |
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q.add(new Integer(1)); |
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assertFalse(q.isEmpty()); |
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q.add(new Integer(2)); |
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q.remove(); |
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q.remove(); |
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assertTrue(q.isEmpty()); |
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} |
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|
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/** |
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* size changes when elements added and removed |
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*/ |
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public void testSize() { |
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PriorityQueue q = populatedQueue(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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assertEquals(SIZE - i, q.size()); |
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q.remove(); |
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} |
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for (int i = 0; i < SIZE; ++i) { |
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assertEquals(i, q.size()); |
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q.add(new Integer(i)); |
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} |
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} |
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|
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/** |
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* offer(null) throws NPE |
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*/ |
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public void testOfferNull() { |
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PriorityQueue q = new PriorityQueue(1); |
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try { |
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q.offer(null); |
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shouldThrow(); |
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} catch (NullPointerException success) {} |
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} |
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|
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/** |
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* add(null) throws NPE |
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*/ |
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public void testAddNull() { |
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PriorityQueue q = new PriorityQueue(1); |
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try { |
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q.add(null); |
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shouldThrow(); |
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} catch (NullPointerException success) {} |
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} |
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|
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/** |
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* Offer of comparable element succeeds |
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*/ |
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public void testOffer() { |
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PriorityQueue q = new PriorityQueue(1); |
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assertTrue(q.offer(zero)); |
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assertTrue(q.offer(one)); |
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} |
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|
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/** |
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* Offer of non-Comparable throws CCE |
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*/ |
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public void testOfferNonComparable() { |
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PriorityQueue q = new PriorityQueue(1); |
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try { |
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q.offer(new Object()); |
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shouldThrow(); |
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} catch (ClassCastException success) { |
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assertTrue(q.isEmpty()); |
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assertEquals(0, q.size()); |
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assertNull(q.poll()); |
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} |
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} |
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|
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/** |
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* add of comparable succeeds |
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*/ |
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public void testAdd() { |
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PriorityQueue q = new PriorityQueue(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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assertEquals(i, q.size()); |
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assertTrue(q.add(new Integer(i))); |
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} |
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} |
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|
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/** |
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* addAll(null) throws NPE |
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*/ |
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public void testAddAll1() { |
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PriorityQueue q = new PriorityQueue(1); |
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try { |
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q.addAll(null); |
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shouldThrow(); |
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} catch (NullPointerException success) {} |
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} |
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|
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/** |
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* addAll of a collection with null elements throws NPE |
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*/ |
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public void testAddAll2() { |
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PriorityQueue q = new PriorityQueue(SIZE); |
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try { |
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q.addAll(Arrays.asList(new Integer[SIZE])); |
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shouldThrow(); |
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} catch (NullPointerException success) {} |
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} |
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|
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/** |
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* addAll of a collection with any null elements throws NPE after |
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* possibly adding some elements |
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*/ |
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public void testAddAll3() { |
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PriorityQueue q = new PriorityQueue(SIZE); |
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Integer[] ints = new Integer[SIZE]; |
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for (int i = 0; i < SIZE - 1; ++i) |
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ints[i] = new Integer(i); |
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try { |
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q.addAll(Arrays.asList(ints)); |
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shouldThrow(); |
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} catch (NullPointerException success) {} |
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} |
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|
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/** |
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* Queue contains all elements of successful addAll |
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*/ |
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public void testAddAll5() { |
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Integer[] empty = new Integer[0]; |
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Integer[] ints = new Integer[SIZE]; |
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for (int i = 0; i < SIZE; ++i) |
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ints[i] = new Integer(SIZE - 1 - i); |
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PriorityQueue q = new PriorityQueue(SIZE); |
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assertFalse(q.addAll(Arrays.asList(empty))); |
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assertTrue(q.addAll(Arrays.asList(ints))); |
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for (int i = 0; i < SIZE; ++i) |
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assertEquals(new Integer(i), q.poll()); |
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} |
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|
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/** |
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* poll succeeds unless empty |
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*/ |
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public void testPoll() { |
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PriorityQueue q = populatedQueue(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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assertEquals(i, q.poll()); |
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} |
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assertNull(q.poll()); |
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} |
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|
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/** |
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* peek returns next element, or null if empty |
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*/ |
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public void testPeek() { |
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PriorityQueue q = populatedQueue(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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assertEquals(i, q.peek()); |
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assertEquals(i, q.poll()); |
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assertTrue(q.peek() == null || |
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!q.peek().equals(i)); |
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} |
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assertNull(q.peek()); |
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} |
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|
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/** |
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* element returns next element, or throws NSEE if empty |
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*/ |
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public void testElement() { |
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PriorityQueue q = populatedQueue(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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assertEquals(i, q.element()); |
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assertEquals(i, q.poll()); |
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} |
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try { |
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q.element(); |
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shouldThrow(); |
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} catch (NoSuchElementException success) {} |
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} |
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|
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/** |
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* remove removes next element, or throws NSEE if empty |
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*/ |
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public void testRemove() { |
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PriorityQueue q = populatedQueue(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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assertEquals(i, q.remove()); |
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} |
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try { |
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q.remove(); |
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shouldThrow(); |
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} catch (NoSuchElementException success) {} |
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} |
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|
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/** |
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* remove(x) removes x and returns true if present |
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*/ |
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public void testRemoveElement() { |
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PriorityQueue q = populatedQueue(SIZE); |
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for (int i = 1; i < SIZE; i += 2) { |
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assertTrue(q.contains(i)); |
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assertTrue(q.remove(i)); |
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assertFalse(q.contains(i)); |
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assertTrue(q.contains(i - 1)); |
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} |
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for (int i = 0; i < SIZE; i += 2) { |
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assertTrue(q.contains(i)); |
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assertTrue(q.remove(i)); |
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assertFalse(q.contains(i)); |
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assertFalse(q.remove(i + 1)); |
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assertFalse(q.contains(i + 1)); |
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} |
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assertTrue(q.isEmpty()); |
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} |
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|
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/** |
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* contains(x) reports true when elements added but not yet removed |
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*/ |
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public void testContains() { |
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PriorityQueue q = populatedQueue(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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assertTrue(q.contains(new Integer(i))); |
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q.poll(); |
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assertFalse(q.contains(new Integer(i))); |
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} |
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} |
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|
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/** |
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* clear removes all elements |
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*/ |
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public void testClear() { |
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PriorityQueue q = populatedQueue(SIZE); |
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q.clear(); |
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assertTrue(q.isEmpty()); |
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assertEquals(0, q.size()); |
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q.add(new Integer(1)); |
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assertFalse(q.isEmpty()); |
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q.clear(); |
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assertTrue(q.isEmpty()); |
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} |
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|
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/** |
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* containsAll(c) is true when c contains a subset of elements |
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*/ |
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public void testContainsAll() { |
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PriorityQueue q = populatedQueue(SIZE); |
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PriorityQueue p = new PriorityQueue(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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assertTrue(q.containsAll(p)); |
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assertFalse(p.containsAll(q)); |
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p.add(new Integer(i)); |
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} |
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assertTrue(p.containsAll(q)); |
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} |
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|
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/** |
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* retainAll(c) retains only those elements of c and reports true if changed |
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*/ |
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public void testRetainAll() { |
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PriorityQueue q = populatedQueue(SIZE); |
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PriorityQueue p = populatedQueue(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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boolean changed = q.retainAll(p); |
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if (i == 0) |
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assertFalse(changed); |
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else |
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assertTrue(changed); |
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|
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assertTrue(q.containsAll(p)); |
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assertEquals(SIZE - i, q.size()); |
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p.remove(); |
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} |
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} |
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|
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/** |
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* removeAll(c) removes only those elements of c and reports true if changed |
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*/ |
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public void testRemoveAll() { |
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for (int i = 1; i < SIZE; ++i) { |
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PriorityQueue q = populatedQueue(SIZE); |
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PriorityQueue p = populatedQueue(i); |
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assertTrue(q.removeAll(p)); |
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assertEquals(SIZE - i, q.size()); |
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for (int j = 0; j < i; ++j) { |
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Integer x = (Integer)(p.remove()); |
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assertFalse(q.contains(x)); |
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} |
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} |
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} |
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|
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/** |
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* toArray contains all elements |
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*/ |
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public void testToArray() { |
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PriorityQueue q = populatedQueue(SIZE); |
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Object[] o = q.toArray(); |
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Arrays.sort(o); |
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for (int i = 0; i < o.length; i++) |
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assertSame(o[i], q.poll()); |
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} |
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|
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/** |
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* toArray(a) contains all elements |
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*/ |
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public void testToArray2() { |
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PriorityQueue<Integer> q = populatedQueue(SIZE); |
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Integer[] ints = new Integer[SIZE]; |
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Integer[] array = q.toArray(ints); |
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assertSame(ints, array); |
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Arrays.sort(ints); |
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for (int i = 0; i < ints.length; i++) |
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assertSame(ints[i], q.poll()); |
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} |
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|
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/** |
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* iterator iterates through all elements |
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*/ |
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public void testIterator() { |
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PriorityQueue q = populatedQueue(SIZE); |
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Iterator it = q.iterator(); |
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int i; |
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for (i = 0; it.hasNext(); i++) |
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assertTrue(q.contains(it.next())); |
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assertEquals(i, SIZE); |
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assertIteratorExhausted(it); |
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} |
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|
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/** |
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* iterator of empty collection has no elements |
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*/ |
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public void testEmptyIterator() { |
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assertIteratorExhausted(new PriorityQueue().iterator()); |
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} |
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|
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/** |
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* iterator.remove removes current element |
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*/ |
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public void testIteratorRemove() { |
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final PriorityQueue q = new PriorityQueue(3); |
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q.add(new Integer(2)); |
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q.add(new Integer(1)); |
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q.add(new Integer(3)); |
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|
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Iterator it = q.iterator(); |
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it.next(); |
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it.remove(); |
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|
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it = q.iterator(); |
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assertEquals(it.next(), new Integer(2)); |
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assertEquals(it.next(), new Integer(3)); |
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assertFalse(it.hasNext()); |
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} |
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|
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/** |
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* toString contains toStrings of elements |
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*/ |
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public void testToString() { |
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PriorityQueue q = populatedQueue(SIZE); |
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String s = q.toString(); |
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for (int i = 0; i < SIZE; ++i) { |
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assertTrue(s.contains(String.valueOf(i))); |
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} |
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} |
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|
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/** |
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* A deserialized serialized queue has same elements |
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*/ |
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public void testSerialization() throws Exception { |
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Queue x = populatedQueue(SIZE); |
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Queue y = serialClone(x); |
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|
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assertNotSame(x, y); |
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assertEquals(x.size(), y.size()); |
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while (!x.isEmpty()) { |
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assertFalse(y.isEmpty()); |
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assertEquals(x.remove(), y.remove()); |
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} |
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assertTrue(y.isEmpty()); |
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} |
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} |