| | | 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 | | using LeetCode.Core.Models; |
| | | 13 | | |
| | | 14 | | namespace LeetCode.Algorithms.CousinsInBinaryTree2; |
| | | 15 | | |
| | | 16 | | /// <inheritdoc /> |
| | | 17 | | public sealed class CousinsInBinaryTree2BreadthFirstSearch : ICousinsInBinaryTree2 |
| | | 18 | | { |
| | | 19 | | /// <summary> |
| | | 20 | | /// Time complexity - O(n), where n is the number of nodes in the binary tree |
| | | 21 | | /// Space complexity - O(h), where h is the height of the tree |
| | | 22 | | /// </summary> |
| | | 23 | | /// <param name="root"></param> |
| | | 24 | | /// <returns></returns> |
| | | 25 | | public TreeNode ReplaceValueInTree(TreeNode root) |
| | 2 | 26 | | { |
| | 2 | 27 | | var queue = new Queue<TreeNode>(); |
| | | 28 | | |
| | 2 | 29 | | queue.Enqueue(root); |
| | | 30 | | |
| | 2 | 31 | | var levelSums = new List<int>(); |
| | | 32 | | |
| | 7 | 33 | | while (queue.Count > 0) |
| | 5 | 34 | | { |
| | 5 | 35 | | var levelSum = 0; |
| | 5 | 36 | | var levelSize = queue.Count; |
| | | 37 | | |
| | 28 | 38 | | for (var i = 0; i < levelSize; i++) |
| | 9 | 39 | | { |
| | 9 | 40 | | var currentNode = queue.Dequeue(); |
| | | 41 | | |
| | 9 | 42 | | levelSum += currentNode.val; |
| | | 43 | | |
| | 9 | 44 | | if (currentNode.left != null) |
| | 3 | 45 | | { |
| | 3 | 46 | | queue.Enqueue(currentNode.left); |
| | 3 | 47 | | } |
| | | 48 | | |
| | 9 | 49 | | if (currentNode.right != null) |
| | 4 | 50 | | { |
| | 4 | 51 | | queue.Enqueue(currentNode.right); |
| | 4 | 52 | | } |
| | 9 | 53 | | } |
| | | 54 | | |
| | 5 | 55 | | levelSums.Add(levelSum); |
| | 5 | 56 | | } |
| | | 57 | | |
| | 2 | 58 | | queue.Enqueue(root); |
| | | 59 | | |
| | 2 | 60 | | var levelIndex = 1; |
| | | 61 | | |
| | 2 | 62 | | root.val = 0; |
| | | 63 | | |
| | 7 | 64 | | while (queue.Count > 0) |
| | 5 | 65 | | { |
| | 5 | 66 | | var levelSize = queue.Count; |
| | | 67 | | |
| | 28 | 68 | | for (var i = 0; i < levelSize; i++) |
| | 9 | 69 | | { |
| | 9 | 70 | | var currentNode = queue.Dequeue(); |
| | | 71 | | |
| | 9 | 72 | | var sum = (currentNode.left?.val ?? 0) + (currentNode.right?.val ?? 0); |
| | | 73 | | |
| | 9 | 74 | | if (currentNode.left != null) |
| | 3 | 75 | | { |
| | 3 | 76 | | currentNode.left.val = levelSums[levelIndex] - sum; |
| | | 77 | | |
| | 3 | 78 | | queue.Enqueue(currentNode.left); |
| | 3 | 79 | | } |
| | | 80 | | |
| | 9 | 81 | | if (currentNode.right != null) |
| | 4 | 82 | | { |
| | 4 | 83 | | currentNode.right.val = levelSums[levelIndex] - sum; |
| | | 84 | | |
| | 4 | 85 | | queue.Enqueue(currentNode.right); |
| | 4 | 86 | | } |
| | 9 | 87 | | } |
| | | 88 | | |
| | 5 | 89 | | levelIndex++; |
| | 5 | 90 | | } |
| | | 91 | | |
| | 2 | 92 | | return root; |
| | 2 | 93 | | } |
| | | 94 | | } |