| | | 1 | | // -------------------------------------------------------------------------------- |
| | | 2 | | // Copyright (C) 2026 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.EqualSumGridPartition1; |
| | | 13 | | |
| | | 14 | | /// <inheritdoc /> |
| | | 15 | | public sealed class EqualSumGridPartition1PrefixSum : IEqualSumGridPartition1 |
| | | 16 | | { |
| | | 17 | | /// <summary> |
| | | 18 | | /// Time complexity - O(m * n) |
| | | 19 | | /// Space complexity - O(1) |
| | | 20 | | /// </summary> |
| | | 21 | | /// <param name="grid"></param> |
| | | 22 | | /// <returns></returns> |
| | | 23 | | public bool CanPartitionGrid(int[][] grid) |
| | 2 | 24 | | { |
| | 2 | 25 | | var m = grid.Length; |
| | 2 | 26 | | var n = grid[0].Length; |
| | | 27 | | |
| | 2 | 28 | | long totalSum = 0; |
| | | 29 | | |
| | 12 | 30 | | for (var i = 0; i < m; i++) |
| | 4 | 31 | | { |
| | 4 | 32 | | var row = grid[i]; |
| | | 33 | | |
| | 24 | 34 | | for (var j = 0; j < n; j++) |
| | 8 | 35 | | { |
| | 8 | 36 | | var value = row[j]; |
| | | 37 | | |
| | 8 | 38 | | totalSum += value; |
| | 8 | 39 | | } |
| | 4 | 40 | | } |
| | | 41 | | |
| | 2 | 42 | | long topSum = 0; |
| | 2 | 43 | | var bottomSum = totalSum; |
| | | 44 | | |
| | 6 | 45 | | for (var i = 0; i < m - 1; i++) |
| | 2 | 46 | | { |
| | 2 | 47 | | var row = grid[i]; |
| | | 48 | | |
| | 12 | 49 | | for (var j = 0; j < n; j++) |
| | 4 | 50 | | { |
| | 4 | 51 | | var value = row[j]; |
| | | 52 | | |
| | 4 | 53 | | topSum += value; |
| | 4 | 54 | | bottomSum -= value; |
| | 4 | 55 | | } |
| | | 56 | | |
| | 2 | 57 | | if (topSum == bottomSum) |
| | 1 | 58 | | { |
| | 1 | 59 | | return true; |
| | | 60 | | } |
| | 1 | 61 | | } |
| | | 62 | | |
| | 1 | 63 | | long leftSum = 0; |
| | 1 | 64 | | var rightSum = totalSum; |
| | | 65 | | |
| | 4 | 66 | | for (var j = 0; j < n - 1; j++) |
| | 1 | 67 | | { |
| | 6 | 68 | | for (var i = 0; i < m; i++) |
| | 2 | 69 | | { |
| | 2 | 70 | | var value = grid[i][j]; |
| | | 71 | | |
| | 2 | 72 | | leftSum += value; |
| | 2 | 73 | | rightSum -= value; |
| | 2 | 74 | | } |
| | | 75 | | |
| | 1 | 76 | | if (leftSum == rightSum) |
| | 0 | 77 | | { |
| | 0 | 78 | | return true; |
| | | 79 | | } |
| | 1 | 80 | | } |
| | | 81 | | |
| | 1 | 82 | | return false; |
| | 2 | 83 | | } |
| | | 84 | | } |