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/* |
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* Written by Josh Bloch of Google Inc. and released to the public domain, |
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* as explained at http://creativecommons.org/publicdomain/zero/1.0/. |
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*/ |
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|
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import java.io.*; |
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import java.util.*; |
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|
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/** |
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* Interface-based Deque tester. This test currently makes three |
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* assumptions about the implementation under test: |
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* |
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* 1) It has no size limitation. |
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* 2) It implements Serializable. |
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* 3) It has a conventional (Collection) constructor. |
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* |
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* All of these assumptions could be relaxed. |
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*/ |
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public class DequeBash { |
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static int seed = 7; |
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static int nextTail = 0; |
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static int nextHead = -1; |
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static int size() { return nextTail - nextHead - 1; } |
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|
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static int random(int bound) { |
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int x = seed; |
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int t = (x % 127773) * 16807 - (x / 127773) * 2836; |
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seed = (t > 0) ? t : t + 0x7fffffff; |
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return (t & 0x7fffffff) % bound; |
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} |
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|
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static int random() { |
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int x = seed; |
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int t = (x % 127773) * 16807 - (x / 127773) * 2836; |
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seed = (t > 0) ? t : t + 0x7fffffff; |
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return (t & 0x7fffffff); |
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} |
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|
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public static void main(String[] args) throws Exception { |
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Class<?> cls = Class.forName(args[0]); |
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int n = 1000000; |
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|
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for (int j = 0; j < 3; ++j) { |
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@SuppressWarnings("unchecked") |
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Deque<Integer> deque = (Deque<Integer>) cls.newInstance(); |
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nextTail = 0; |
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nextHead = -1; |
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long start = System.nanoTime(); |
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mainTest(deque, n); |
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long end = System.nanoTime(); |
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long elapsedTimeMillis = (end - start) / (1000L * 1000L); |
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System.out.printf("Time: %d ms%n", elapsedTimeMillis); |
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if (deque.isEmpty()) System.out.print(" "); |
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} |
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} |
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|
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static void mainTest(Deque<Integer> deque, int n) throws Exception { |
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/* |
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* Perform a random sequence of operations, keeping contiguous |
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* sequence of integers on the deque. |
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*/ |
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for (int i = 0; i < n; i++) { |
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sizeTests(deque); |
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randomOp(deque); |
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|
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// Test iterator occasionally |
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if ((i & 1023) == 0) { |
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testIter(deque); |
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testDescendingIter(deque); |
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} |
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|
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// Test serialization and copying |
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if ((i & 4095) == 0) { |
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testEqual(deque, serialClone(deque)); |
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testEqual(deque, copyConstructorClone(deque)); |
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} |
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|
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// Test fancy removal stuff once in a blue moon |
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if ((i & 8191) == 0) |
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testRemove(deque); |
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} |
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|
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// Stupid tests for clear, toString |
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deque.clear(); |
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testEmpty(deque); |
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Collection<Integer> c = Arrays.asList(1, 2, 3); |
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deque.addAll(c); |
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if (!deque.toString().equals("[1, 2, 3]")) |
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throw new Exception("Deque.toString(): " + deque.toString()); |
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} |
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|
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static void testIter(Deque<Integer> deque) throws Exception { |
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int next = nextHead + 1; |
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int count = 0; |
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for (int j : deque) { |
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if (j != next++) |
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throw new Exception("Element "+ j + " != " + (next-1)); |
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count++; |
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} |
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if (count != size()) |
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throw new Exception("Count " + count + " != " + size()); |
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} |
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|
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static void testDescendingIter(Deque<Integer> deque) throws Exception { |
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int next = deque.size() + nextHead; |
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int count = 0; |
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for (Iterator<Integer> it = deque.descendingIterator(); it.hasNext();) { |
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int j = it.next(); |
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if (j != next--) |
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throw new Exception("Element "+ j + " != " + (next-1)); |
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count++; |
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} |
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if (count != size()) |
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throw new Exception("Count " + count + " != " + size()); |
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} |
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|
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static void sizeTests(Deque<Integer> deque) throws Exception { |
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if (deque.size() != size()) |
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throw new Exception("Size: " + deque.size() + |
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", expecting " + size()); |
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if (deque.isEmpty() != (size() == 0)) |
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throw new Exception( |
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"IsEmpty " + deque.isEmpty() + ", size " + size()); |
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// Check head and tail |
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if (size() == 0) |
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testEmpty(deque); |
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else |
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nonEmptyTest(deque); |
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|
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} |
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|
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static void nonEmptyTest(Deque<Integer> deque) throws Exception { |
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if (deque.getFirst() != nextHead + 1) |
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throw new Exception("getFirst got: " + |
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deque.getFirst() + " expecting " + (nextHead + 1)); |
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if (deque.element() != nextHead + 1) |
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throw new Exception("element got: " + deque.element() + |
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" expecting " + (nextHead + 1)); |
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if (deque.peekFirst() != nextHead + 1) |
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throw new Exception("peekFirst got: "+deque.peekFirst() + |
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" expecting " + (nextHead + 1)); |
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if (deque.peek() != nextHead + 1) |
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throw new Exception("peek got: " + deque.peek() + |
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" expecting " + (nextHead + 1)); |
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|
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if (deque.peekLast() != nextTail - 1) |
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throw new Exception("peekLast got: " + deque.peekLast() + |
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" expecting " + (nextTail - 1)); |
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if (deque.getLast() != nextTail - 1) |
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throw new Exception("getLast got: " + |
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deque.getLast() + " expecting " + (nextTail - 1)); |
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} |
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|
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static void randomOp(Deque<Integer> deque) throws Exception { |
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|
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// Perform a random operation |
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switch (random() & 3) { |
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case 0: |
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switch (random() & 3) { |
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case 0: deque.addLast(nextTail++); break; |
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case 1: deque.offerLast(nextTail++); break; |
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case 2: deque.offer(nextTail++); break; |
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case 3: deque.add(nextTail++); break; |
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default: throw new Exception("How'd we get here"); |
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} |
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break; |
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case 1: |
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if (size() == 0) { |
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int result = 666; |
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boolean threw = false; |
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try { |
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switch (random(3)) { |
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case 0: result = deque.removeFirst(); break; |
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case 1: result = deque.remove(); break; |
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case 2: result = deque.pop(); break; |
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default: throw new Exception("How'd we get here"); |
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} |
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} catch (NoSuchElementException e) { |
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threw = true; |
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} |
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if (!threw) |
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throw new Exception("Remove-no exception: " + result); |
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} else { // deque nonempty |
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int result = -1; |
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switch (random(5)) { |
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case 0: result = deque.removeFirst(); break; |
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case 1: result = deque.remove(); break; |
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case 2: result = deque.pop(); break; |
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case 3: result = deque.pollFirst(); break; |
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case 4: result = deque.poll(); break; |
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default: throw new Exception("How'd we get here"); |
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} |
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if (result != ++nextHead) |
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throw new Exception( |
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"Removed "+ result + " expecting "+(nextHead - 1)); |
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} |
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break; |
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case 2: |
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switch (random(3)) { |
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case 0: deque.addFirst(nextHead--); break; |
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case 1: deque.offerFirst(nextHead--); break; |
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case 2: deque.push(nextHead--); break; |
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default: throw new Exception("How'd we get here"); |
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} |
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break; |
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case 3: |
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if (size() == 0) { |
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int result = -1; |
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boolean threw = false; |
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try { |
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result = deque.removeLast(); |
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} catch (NoSuchElementException e) { |
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threw = true; |
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} |
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if (!threw) |
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throw new Exception("Remove-no exception: " + result); |
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} else { // deque nonempty |
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int result = ((random() & 1) == 0 ? |
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deque.removeLast() : deque.pollLast()); |
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if (result != --nextTail) |
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throw new Exception( |
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"Removed "+ result + " expecting "+(nextTail + 1)); |
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} |
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break; |
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default: |
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throw new Exception("How'd we get here"); |
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} |
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} |
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|
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private static void testEqual(Deque<Integer> d1, Deque<Integer> d2) |
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throws Exception |
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{ |
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if (d1.size() != d2.size()) |
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throw new Exception("Size " + d1.size() + " != " + d2.size()); |
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Iterator<Integer> it = d2.iterator(); |
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for (int i : d1) { |
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int j = it.next(); |
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if (j != i) |
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throw new Exception("Element " + j + " != " + i); |
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} |
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|
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for (int i : d1) |
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if (!d2.contains(i)) |
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throw new Exception("d2 doesn't contain " + i); |
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for (int i : d2) |
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if (!d1.contains(i)) |
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throw new Exception("d2 doesn't contain " + i); |
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|
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if (d1.contains(Integer.MIN_VALUE)) |
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throw new Exception("d2 contains Integer.MIN_VALUE"); |
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if (d2.contains(Integer.MIN_VALUE)) |
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throw new Exception("d2 contains Integer.MIN_VALUE"); |
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if (d1.contains(null)) |
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throw new Exception("d1 contains null"); |
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if (d2.contains(null)) |
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throw new Exception("d2 contains null"); |
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|
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if (!d1.containsAll(d2)) |
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throw new Exception("d1 doesn't contain all of d2"); |
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if (!d2.containsAll(d1)) |
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throw new Exception("d2 doesn't contain all of d1"); |
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Collection<Integer> c = Collections.singleton(Integer.MIN_VALUE); |
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if (d1.containsAll(c)) |
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throw new Exception("d1 contains all of {Integer.MIN_VALUE }"); |
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if (d2.containsAll(c)) |
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throw new Exception("d2 contains all of {Integer.MIN_VALUE }"); |
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} |
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|
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@SuppressWarnings("unchecked") |
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private static <T> T copyConstructorClone(T o) throws Exception { |
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return (T) o.getClass().getConstructor(Collection.class).newInstance(o); |
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} |
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|
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@SuppressWarnings("unchecked") |
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private static <T> T serialClone(T o) throws Exception { |
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ByteArrayOutputStream bos = new ByteArrayOutputStream(); |
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ObjectOutputStream oos = new ObjectOutputStream(bos); |
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oos.writeObject(o); |
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oos.flush(); |
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oos.close(); |
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ByteArrayInputStream bin = |
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new ByteArrayInputStream(bos.toByteArray()); |
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ObjectInputStream ois = new ObjectInputStream(bin); |
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return (T) ois.readObject(); |
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} |
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|
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private static void testRemove(Deque<Integer> deque) throws Exception { |
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Deque<Integer> copy = ((random() & 1) == 0) ? |
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copyConstructorClone(deque) : |
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serialClone(deque); |
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|
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int numRemoved = 0; |
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for (Iterator<Integer> it = copy.iterator(); it.hasNext(); ) { |
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if ((it.next() & 1) == 0) { |
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it.remove(); |
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numRemoved++; |
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} |
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} |
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|
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if (copy.size() + numRemoved != size()) |
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throw new Exception((copy.size() + numRemoved) + " != " + size()); |
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for (int i : copy) |
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if ((i & 1) == 0) |
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throw new Exception("Even number still present: " + i); |
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|
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List<Integer> elements = Arrays.asList(copy.toArray(new Integer[0])); |
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Collections.shuffle(elements); |
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for (int e : elements) { |
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if (!copy.contains(e)) |
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throw new Exception(e + " missing."); |
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|
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boolean removed = false; |
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switch (random(3)) { |
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case 0: removed = copy.remove(e); break; |
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case 1: removed = copy.removeFirstOccurrence(e); break; |
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case 2: removed = copy.removeLastOccurrence(e); break; |
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default: throw new Exception("How'd we get here"); |
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} |
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if (!removed) |
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throw new Exception(e + " not removed."); |
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|
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if (copy.contains(e)) |
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throw new Exception(e + " present after removal."); |
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} |
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|
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testEmpty(copy); |
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|
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copy = copyConstructorClone(deque); |
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copy.retainAll(deque); |
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testEqual(deque, copy); |
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copy.removeAll(deque); |
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testEmpty(copy); |
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} |
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|
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static boolean checkedThrows; |
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|
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private static void testEmpty(Deque<Integer> deque) throws Exception { |
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if (!deque.isEmpty()) |
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throw new Exception("Deque isn't empty"); |
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if (deque.size() != 0) |
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throw new Exception("Deque size isn't zero"); |
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if (!(deque.pollFirst() == null)) |
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throw new Exception("pollFirst lies"); |
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if (!(deque.poll() == null)) |
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throw new Exception("poll lies"); |
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if (!(deque.peekFirst() == null)) |
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throw new Exception("peekFirst lies"); |
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if (!(deque.peek() == null)) |
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throw new Exception("peek lies"); |
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if (!(deque.pollLast() == null)) |
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throw new Exception("pollLast lies"); |
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if (!(deque.peekLast() == null)) |
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throw new Exception("peekLast lies"); |
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|
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if (!checkedThrows) { |
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checkedThrows = true; |
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boolean threw = false; |
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int result = 666; |
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try { |
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result = ((random() & 1) == 0 ? |
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deque.getFirst() : deque.element()); |
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} catch (NoSuchElementException e) { |
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threw = true; |
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} |
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if (!threw) |
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throw new Exception("getFirst-no exception: "+result); |
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threw = false; |
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try { |
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result = deque.getLast(); |
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} catch (NoSuchElementException e) { |
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threw = true; |
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} |
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if (!threw) |
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throw new Exception("getLast-no exception: "+result); |
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} |
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|
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} |
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} |
