| | | 1 | | // -------------------------------------------------------------------------------- |
| | | 2 | | // Copyright (C) 2025 Eugene Eremeev (also known as Yevhenii Yeriemeieiv). |
| | | 3 | | // All Rights Reserved. |
| | | 4 | | // -------------------------------------------------------------------------------- |
| | | 5 | | // This software is the confidential and proprietary information of Eugene Eremeev |
| | | 6 | | // (also known as Yevhenii Yeriemeieiv) ("Confidential Information"). You shall not |
| | | 7 | | // disclose such Confidential Information and shall use it only in accordance with |
| | | 8 | | // the terms of the license agreement you entered into with Eugene Eremeev (also |
| | | 9 | | // known as Yevhenii Yeriemeieiv). |
| | | 10 | | // -------------------------------------------------------------------------------- |
| | | 11 | | |
| | | 12 | | namespace LeetCode.Algorithms.SortAnArray; |
| | | 13 | | |
| | | 14 | | /// <inheritdoc /> |
| | | 15 | | public class SortAnArrayMergeSort : ISortAnArray |
| | | 16 | | { |
| | | 17 | | /// <summary> |
| | | 18 | | /// Time complexity - O(n log n) |
| | | 19 | | /// Space complexity - O(n) |
| | | 20 | | /// </summary> |
| | | 21 | | /// <param name="nums"></param> |
| | | 22 | | /// <returns></returns> |
| | | 23 | | public int[] SortArray(int[] nums) |
| | 2 | 24 | | { |
| | 2 | 25 | | SortArray(nums, 0, nums.Length - 1); |
| | | 26 | | |
| | 2 | 27 | | return nums; |
| | 2 | 28 | | } |
| | | 29 | | |
| | | 30 | | private static void SortArray(IList<int> array, int left, int right) |
| | 18 | 31 | | { |
| | 18 | 32 | | if (left >= right) |
| | 10 | 33 | | { |
| | 10 | 34 | | return; |
| | | 35 | | } |
| | | 36 | | |
| | 8 | 37 | | var middle = (left + right) / 2; |
| | | 38 | | |
| | 8 | 39 | | SortArray(array, left, middle); |
| | 8 | 40 | | SortArray(array, middle + 1, right); |
| | 8 | 41 | | Merge(array, left, middle, right); |
| | 18 | 42 | | } |
| | | 43 | | |
| | | 44 | | private static void Merge(IList<int> array, int left, int middle, int right) |
| | 8 | 45 | | { |
| | 8 | 46 | | var leftSize = middle - left + 1; |
| | 8 | 47 | | var rightSize = right - middle; |
| | | 48 | | |
| | 8 | 49 | | var leftArray = array.Skip(left).Take(leftSize).ToArray(); |
| | 8 | 50 | | var rightArray = array.Skip(middle + 1).Take(rightSize).ToArray(); |
| | | 51 | | |
| | 8 | 52 | | var i = 0; |
| | 8 | 53 | | var j = 0; |
| | 8 | 54 | | var k = left; |
| | | 55 | | |
| | 24 | 56 | | while (i < leftSize && j < rightSize) |
| | 16 | 57 | | { |
| | 16 | 58 | | if (leftArray[i] > rightArray[j]) |
| | 11 | 59 | | { |
| | 11 | 60 | | array[k] = rightArray[j]; |
| | | 61 | | |
| | 11 | 62 | | j++; |
| | 11 | 63 | | } |
| | | 64 | | else |
| | 5 | 65 | | { |
| | 5 | 66 | | array[k] = leftArray[i]; |
| | | 67 | | |
| | 5 | 68 | | i++; |
| | 5 | 69 | | } |
| | | 70 | | |
| | 16 | 71 | | k++; |
| | 16 | 72 | | } |
| | | 73 | | |
| | 16 | 74 | | while (i < leftSize) |
| | 8 | 75 | | { |
| | 8 | 76 | | array[k] = leftArray[i]; |
| | | 77 | | |
| | 8 | 78 | | i++; |
| | 8 | 79 | | k++; |
| | 8 | 80 | | } |
| | | 81 | | |
| | 8 | 82 | | while (j < rightSize) |
| | 0 | 83 | | { |
| | 0 | 84 | | array[k] = rightArray[j]; |
| | | 85 | | |
| | 0 | 86 | | j++; |
| | 0 | 87 | | k++; |
| | 0 | 88 | | } |
| | 8 | 89 | | } |
| | | 90 | | } |