lrn@google.com
047b32681d
R=sgjesse@google.com Review URL: https://codereview.chromium.org//113883002 git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@31260 260f80e4-7a28-3924-810f-c04153c831b5
272 lines
8.6 KiB
Dart
272 lines
8.6 KiB
Dart
// Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file
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// for details. All rights reserved. Use of this source code is governed by a
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// BSD-style license that can be found in the LICENSE file.
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/// Tests algorithm utilities.
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import "package:collection/collection.dart";
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import "package:unittest/unittest.dart";
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import 'dart:math';
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void main() {
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void testShuffle(List list) {
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List copy = list.toList();
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shuffle(list);
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expect(new UnorderedIterableEquality().equals(list, copy), isTrue);
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}
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test("Shuffle 0", () {
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testShuffle([]);
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});
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test("Shuffle 1", () {
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testShuffle([1]);
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});
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test("Shuffle 3", () {
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testShuffle([1, 2, 3]);
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});
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test("Shuffle 10", () {
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testShuffle([1, 2, 3, 4, 5, 1, 3, 5, 7, 9]);
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});
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test("Shuffle shuffles", () {
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List l = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16];
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List c = l.toList();
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int count = 0;
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do {
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shuffle(l);
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if (!const ListEquality().equals(c, l)) return;
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// Odds of not changing the order should be one in ~ 16! ~= 2e+13.
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// Repeat this 10 times, and the odds of accidentally shuffling to the
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// same result every time is disappearingly tiny.
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count++;
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// If this happens even once, it's ok to report it.
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print("Failed shuffle $count times");
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if (count == 10) fail("Shuffle didn't change order.");
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} while (true);
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});
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test("Shuffle sublist", (){
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List l = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16];
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List c = l.toList();
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shuffle(l, 4, 12);
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expect(const IterableEquality().equals(l.getRange(0, 4),
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c.getRange(0, 4)), isTrue);
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expect(const IterableEquality().equals(l.getRange(12, 16),
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c.getRange(12, 16)), isTrue);
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expect(const UnorderedIterableEquality().equals(l.getRange(4, 12),
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c.getRange(4, 12)),
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isTrue);
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});
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test("binsearch0", () {
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expect(binarySearch([], 2), equals(-1));
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});
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test("binsearch1", () {
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expect(binarySearch([5], 2), equals(-1));
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expect(binarySearch([5], 5), equals(0));
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expect(binarySearch([5], 7), equals(-1));
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});
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test("binsearch3", () {
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expect(binarySearch([0, 5, 10], -1), equals(-1));
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expect(binarySearch([0, 5, 10], 0), equals(0));
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expect(binarySearch([0, 5, 10], 2), equals(-1));
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expect(binarySearch([0, 5, 10], 5), equals(1));
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expect(binarySearch([0, 5, 10], 7), equals(-1));
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expect(binarySearch([0, 5, 10], 10), equals(2));
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expect(binarySearch([0, 5, 10], 12), equals(-1));
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});
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test("binsearchCompare0", () {
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expect(binarySearch([], new C(2), compare: compareC), equals(-1));
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});
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test("binsearchCompare1", () {
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var l1 = [new C(5)];
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expect(binarySearch(l1, new C(2), compare: compareC), equals(-1));
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expect(binarySearch(l1, new C(5), compare: compareC), equals(0));
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expect(binarySearch(l1, new C(7), compare: compareC), equals(-1));
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});
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test("binsearchCompare3", () {
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var l3 = [new C(0), new C(5), new C(10)];
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expect(binarySearch(l3, new C(-1), compare: compareC), equals(-1));
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expect(binarySearch(l3, new C(0), compare: compareC), equals(0));
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expect(binarySearch(l3, new C(2), compare: compareC), equals(-1));
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expect(binarySearch(l3, new C(5), compare: compareC), equals(1));
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expect(binarySearch(l3, new C(7), compare: compareC), equals(-1));
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expect(binarySearch(l3, new C(10), compare: compareC), equals(2));
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expect(binarySearch(l3, new C(12), compare: compareC), equals(-1));
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});
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test("insertionSortRandom", () {
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Random random = new Random();
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for (int i = 0; i < 25; i++) {
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List list = new List(i);
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for (int j = 0; j < i; j++) {
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list[j] = random.nextInt(25); // Expect some equal elements.
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}
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insertionSort(list);
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for (int j = 1; j < i; j++) {
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expect(list[j - 1], lessThanOrEqualTo(list[j]));
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}
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}
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});
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test("insertionSortSubRanges", () {
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List l = [6, 5, 4, 3, 2, 1];
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insertionSort(l, start: 2, end: 4);
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expect(l, equals([6, 5, 3, 4, 2, 1]));
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insertionSort(l, start: 1, end: 1);
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expect(l, equals([6, 5, 3, 4, 2, 1]));
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insertionSort(l, start: 4, end: 6);
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expect(l, equals([6, 5, 3, 4, 1, 2]));
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insertionSort(l, start: 0, end: 2);
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expect(l, equals([5, 6, 3, 4, 1, 2]));
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insertionSort(l, start: 0, end: 6);
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expect(l, equals([1, 2, 3, 4, 5, 6]));
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});
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test("insertionSortSpecialCases", () {
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List l = [6, 6, 6, 6, 6, 6];
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insertionSort(l);
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expect(l, equals([6, 6, 6, 6, 6, 6]));
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l = [6, 6, 3, 3, 0, 0];
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insertionSort(l);
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expect(l, equals([0, 0, 3, 3, 6, 6]));
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});
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test("MergeSortRandom", () {
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Random random = new Random();
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for (int i = 0; i < 250; i += 1) {
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List list = new List(i);
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for (int j = 0; j < i; j++) {
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list[j] = random.nextInt(i); // Expect some equal elements.
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}
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mergeSort(list);
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for (int j = 1; j < i; j++) {
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expect(list[j - 1], lessThanOrEqualTo(list[j]));
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}
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}
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});
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test("MergeSortPreservesOrder", () {
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Random random = new Random();
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// Small case where only insertion call is called,
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// larger case where the internal moving insertion sort is used
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// larger cases with multiple splittings, numbers just around a power of 2.
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for (int size in [8, 50, 511, 512, 513]) {
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List list = new List(size);
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// Class OC compares using id.
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// With size elements with id's in the range 0..size/4, a number of
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// collisions are guaranteed. These should be sorted so that the "order"
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// part of the objects are still in order.
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for (int i = 0; i < size; i++) {
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list[i] = new OC(random.nextInt(size >> 2), i);
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}
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mergeSort(list);
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OC prev = list[0];
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for (int i = 1; i < size; i++) {
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OC next = list[i];
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expect(prev.id, lessThanOrEqualTo(next.id));
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if (next.id == prev.id) {
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expect(prev.order, lessThanOrEqualTo(next.order));
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}
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prev = next;
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}
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// Reverse compare on part of list.
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List copy = list.toList();
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int min = size >> 2;
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int max = size - min;
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mergeSort(list, start: min, end: max, compare: (a, b) => b.compareTo(a));
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prev = list[min];
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for (int i = min + 1; i < max; i++) {
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OC next = list[i];
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expect(prev.id, greaterThanOrEqualTo(next.id));
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if (next.id == prev.id) {
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expect(prev.order, lessThanOrEqualTo(next.order));
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}
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prev = next;
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}
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// Equals on OC objects is identity, so this means the parts before min,
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// and the parts after max, didn't change at all.
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expect(list.sublist(0, min), equals(copy.sublist(0, min)));
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expect(list.sublist(max), equals(copy.sublist(max)));
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}
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});
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test("MergeSortSpecialCases", () {
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for (int size in [511, 512, 513]) {
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// All equal.
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List list = new List(size);
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for (int i = 0; i < size; i++) {
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list[i] = new OC(0, i);
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}
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mergeSort(list);
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for (int i = 0; i < size; i++) {
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expect(list[i].order, equals(i));
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}
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// All but one equal, first.
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list[0] = new OC(1, 0);
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for (int i = 1; i < size; i++) {
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list[i] = new OC(0, i);
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}
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mergeSort(list);
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for (int i = 0; i < size - 1; i++) {
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expect(list[i].order, equals(i + 1));
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}
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expect(list[size - 1].order, equals(0));
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// All but one equal, last.
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for (int i = 0; i < size - 1; i++) {
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list[i] = new OC(0, i);
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}
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list[size - 1] = new OC(-1, size - 1);
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mergeSort(list);
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expect(list[0].order, equals(size - 1));
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for (int i = 1; i < size; i++) {
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expect(list[i].order, equals(i - 1));
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}
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// Reversed.
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for (int i = 0; i < size; i++) {
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list[i] = new OC(size - 1 - i, i);
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}
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mergeSort(list);
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for (int i = 0; i < size; i++) {
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expect(list[i].id, equals(i));
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expect(list[i].order, equals(size - 1 - i));
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}
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}
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});
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test("Reverse", () {
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List l = [6, 5, 4, 3, 2, 1];
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reverse(l, 2, 4);
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expect(l, equals([6, 5, 3, 4, 2, 1]));
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reverse(l, 1, 1);
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expect(l, equals([6, 5, 3, 4, 2, 1]));
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reverse(l, 4, 6);
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expect(l, equals([6, 5, 3, 4, 1, 2]));
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reverse(l, 0, 2);
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expect(l, equals([5, 6, 3, 4, 1, 2]));
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reverse(l, 0, 6);
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expect(l, equals([2, 1, 4, 3, 6, 5]));
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});
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}
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class C {
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final int id;
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C(this.id);
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}
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int compareC(C one, C other) => one.id - other.id;
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class OC implements Comparable<OC> {
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final int id;
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final int order;
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OC(this.id, this.order);
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int compareTo(OC other) => id - other.id;
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String toString() => "OC[$id,$order]";
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}
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