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| 1 | +// https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/description/ |
| 2 | +import 'package:test/test.dart'; |
| 3 | + |
| 4 | +void main() { |
| 5 | + final stopwatch = Stopwatch()..start(); |
| 6 | + runTests(); |
| 7 | + |
| 8 | + /// |
| 9 | + stopwatch.stop(); |
| 10 | + print('Function Execution Time : ${stopwatch.elapsedMicroseconds} micro sec'); |
| 11 | +} |
| 12 | + |
| 13 | +class Solution { |
| 14 | + ////! Binary Search |
| 15 | + ////! The more hard solution with Binary Search TC: O(n*log(n)) |
| 16 | + ////! Accepted And Faster |
| 17 | + List<int> twoSum(List<int> numbers, int target) { |
| 18 | + for (int i = 0; i < numbers.length - 1; i++) { |
| 19 | + final int otherNumber = target - numbers[i]; |
| 20 | + int leftIndex = i + 1; |
| 21 | + int rightIndex = numbers.length - 1; |
| 22 | + |
| 23 | + while (leftIndex <= rightIndex) { |
| 24 | + int mid = leftIndex + (rightIndex - leftIndex) ~/ 2; |
| 25 | + if (numbers[mid] == otherNumber) { |
| 26 | + return [i + 1, mid + 1]; |
| 27 | + } else if (numbers[mid] > otherNumber) { |
| 28 | + rightIndex = mid - 1; |
| 29 | + } else { |
| 30 | + leftIndex = mid + 1; |
| 31 | + } |
| 32 | + } |
| 33 | + } |
| 34 | + |
| 35 | + return []; |
| 36 | + } |
| 37 | + |
| 38 | + ////! Burte Force |
| 39 | + ////! The easy solution --> TC: O(n^2) |
| 40 | + ////! Accepted But Slow |
| 41 | + // List<int> twoSum(List<int> numbers, int target) { |
| 42 | + // for (int i = 0; i < numbers.length; i++) { |
| 43 | + // for (var j = i + 1; j < numbers.length; j++) { |
| 44 | + // if (numbers[i] + numbers[j] == target) { |
| 45 | + // return [i + 1, j + 1]; |
| 46 | + // } else if (numbers[i] + numbers[j] > target) { |
| 47 | + // break; |
| 48 | + // } |
| 49 | + // } |
| 50 | + // } |
| 51 | + |
| 52 | + // return []; |
| 53 | + // } |
| 54 | +} |
| 55 | + |
| 56 | +void runTests() { |
| 57 | + final Solution s = Solution(); |
| 58 | + |
| 59 | + group('Two Sum II - Input Array Is Sorted', () { |
| 60 | + // Basic examples from problem statement |
| 61 | + test('Example 1: [2,7,11,15], target=9 → [1,2]', () { |
| 62 | + expect(s.twoSum([2, 7, 11, 15], 9), equals([1, 2])); |
| 63 | + }); |
| 64 | + |
| 65 | + test('Example 2: [2,3,4], target=6 → [1,3]', () { |
| 66 | + expect(s.twoSum([2, 3, 4], 6), equals([1, 3])); |
| 67 | + }); |
| 68 | + |
| 69 | + test('Example 3: [-1,0], target=-1 → [1,2]', () { |
| 70 | + expect(s.twoSum([-1, 0], -1), equals([1, 2])); |
| 71 | + }); |
| 72 | + |
| 73 | + // Edge cases |
| 74 | + test('Minimum length array: [1,2], target=3 → [1,2]', () { |
| 75 | + expect(s.twoSum([1, 2], 3), equals([1, 2])); |
| 76 | + }); |
| 77 | + |
| 78 | + test('Negative numbers: [-5,-3,-1], target=-8 → [1,2]', () { |
| 79 | + expect(s.twoSum([-5, -3, -1], -8), equals([1, 2])); |
| 80 | + }); |
| 81 | + |
| 82 | + test('Zero sum: [-2,0,1,2], target=0 → [1,4]', () { |
| 83 | + expect(s.twoSum([-2, 0, 1, 2], 0), equals([1, 4])); |
| 84 | + }); |
| 85 | + |
| 86 | + // Duplicate numbers |
| 87 | + test('Duplicate numbers: [1,1,2,3], target=2 → [1,2]', () { |
| 88 | + expect(s.twoSum([1, 1, 2, 3], 2), equals([1, 2])); |
| 89 | + }); |
| 90 | + |
| 91 | + test('Duplicate numbers at solution: [1,2,2,4], target=4 → [2,3]', () { |
| 92 | + expect(s.twoSum([1, 2, 2, 4], 4), equals([2, 3])); |
| 93 | + }); |
| 94 | + |
| 95 | + // Large numbers |
| 96 | + test('Large numbers: [1000,1000], target=2000 → [1,2]', () { |
| 97 | + expect(s.twoSum([1000, 1000], 2000), equals([1, 2])); |
| 98 | + }); |
| 99 | + |
| 100 | + // Large array |
| 101 | + test('Large array', () { |
| 102 | + final nums = List.generate(30000, (i) => i + 1); |
| 103 | + final target = 59999; // 30000 + 29999 |
| 104 | + expect(s.twoSum(nums, target), equals([29999, 30000])); |
| 105 | + }); |
| 106 | + |
| 107 | + // First and last elements |
| 108 | + test('First and last elements: [1,2,3,4,5], target=6 → [1,5]', () { |
| 109 | + expect(s.twoSum([1, 2, 3, 4, 5], 6), equals([1, 5])); |
| 110 | + }); |
| 111 | + |
| 112 | + // Consecutive elements |
| 113 | + test('Consecutive elements: [1,2,3,4], target=7 → [3,4]', () { |
| 114 | + expect(s.twoSum([1, 2, 3, 4], 7), equals([3, 4])); |
| 115 | + }); |
| 116 | + |
| 117 | + test('Minimum target: [-1000,0,1000], target=-1000 → [1,2]', () { |
| 118 | + expect(s.twoSum([-1000, 0, 1000], -1000), equals([1, 2])); |
| 119 | + }); |
| 120 | + |
| 121 | + test('Maximum target: [-1000,0,1000], target=1000 → [2,3]', () { |
| 122 | + expect(s.twoSum([-1000, 0, 1000], 1000), equals([2, 3])); |
| 123 | + }); |
| 124 | + |
| 125 | + // Random cases |
| 126 | + test('Random case 2: [2,4,6,8,10], target=10 → [1,4]', () { |
| 127 | + expect(s.twoSum([2, 4, 6, 8, 10], 10), equals([1, 4])); |
| 128 | + }); |
| 129 | + |
| 130 | + /// Leet code |
| 131 | + test('Leet code: [0,0,3,4], target=0 → [1,2]', () { |
| 132 | + expect(s.twoSum([0, 0, 3, 4], 0), equals([1, 2])); |
| 133 | + }); |
| 134 | + }); |
| 135 | +} |
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