| | | 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.PartitionArrayIntoThreePartsWithEqualSum; |
| | | 13 | | |
| | | 14 | | /// <inheritdoc /> |
| | | 15 | | public class PartitionArrayIntoThreePartsWithEqualSumIterative : IPartitionArrayIntoThreePartsWithEqualSum |
| | | 16 | | { |
| | | 17 | | /// <summary> |
| | | 18 | | /// Time complexity - O(n) |
| | | 19 | | /// Space complexity - O(1) |
| | | 20 | | /// </summary> |
| | | 21 | | /// <param name="arr"></param> |
| | | 22 | | /// <returns></returns> |
| | | 23 | | public bool CanThreePartsEqualSum(int[] arr) |
| | 15 | 24 | | { |
| | 15 | 25 | | var totalSum = arr.Sum(); |
| | | 26 | | |
| | 15 | 27 | | if (totalSum % 3 != 0) |
| | 4 | 28 | | { |
| | 4 | 29 | | return false; |
| | | 30 | | } |
| | | 31 | | |
| | 11 | 32 | | var singleSum = totalSum / 3; |
| | | 33 | | |
| | 11 | 34 | | var firstSum = 0; |
| | | 35 | | |
| | 11 | 36 | | var index = 0; |
| | | 37 | | |
| | 86 | 38 | | for (var i = 0; i < arr.Length; i++) |
| | 40 | 39 | | { |
| | 40 | 40 | | firstSum += arr[i]; |
| | | 41 | | |
| | 40 | 42 | | if (firstSum != singleSum) |
| | 32 | 43 | | { |
| | 32 | 44 | | continue; |
| | | 45 | | } |
| | | 46 | | |
| | 8 | 47 | | index = i + 1; |
| | | 48 | | |
| | 8 | 49 | | break; |
| | | 50 | | } |
| | | 51 | | |
| | 11 | 52 | | if (index >= arr.Length) |
| | 0 | 53 | | { |
| | 0 | 54 | | return false; |
| | | 55 | | } |
| | | 56 | | |
| | 11 | 57 | | var secondSum = 0; |
| | | 58 | | |
| | 100 | 59 | | for (var i = index; i < arr.Length; i++) |
| | 47 | 60 | | { |
| | 47 | 61 | | secondSum += arr[i]; |
| | | 62 | | |
| | 47 | 63 | | if (secondSum != singleSum) |
| | 39 | 64 | | { |
| | 39 | 65 | | continue; |
| | | 66 | | } |
| | | 67 | | |
| | 8 | 68 | | index = i + 1; |
| | | 69 | | |
| | 8 | 70 | | break; |
| | | 71 | | } |
| | | 72 | | |
| | 11 | 73 | | if (index >= arr.Length) |
| | 1 | 74 | | { |
| | 1 | 75 | | return false; |
| | | 76 | | } |
| | | 77 | | |
| | 10 | 78 | | var thirdSum = 0; |
| | | 79 | | |
| | 104 | 80 | | for (var i = index; i < arr.Length; i++) |
| | 49 | 81 | | { |
| | 49 | 82 | | thirdSum += arr[i]; |
| | | 83 | | |
| | 49 | 84 | | if (thirdSum == singleSum) |
| | 7 | 85 | | { |
| | 7 | 86 | | break; |
| | | 87 | | } |
| | 42 | 88 | | } |
| | | 89 | | |
| | 10 | 90 | | return totalSum - firstSum - secondSum - thirdSum == 0; |
| | 15 | 91 | | } |
| | | 92 | | } |