| | | 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.MostStonesRemovedWithSameRowOrColumn; |
| | | 13 | | |
| | | 14 | | /// <inheritdoc /> |
| | | 15 | | public class MostStonesRemovedWithSameRowOrColumnUnionFind : IMostStonesRemovedWithSameRowOrColumn |
| | | 16 | | { |
| | | 17 | | /// <summary> |
| | | 18 | | /// Time complexity - O(n) |
| | | 19 | | /// Space complexity - O(n) |
| | | 20 | | /// </summary> |
| | | 21 | | /// <param name="stones"></param> |
| | | 22 | | /// <returns></returns> |
| | | 23 | | public int RemoveStones(int[][] stones) |
| | 9 | 24 | | { |
| | 9 | 25 | | var unionFind = new UnionFind(20002); |
| | | 26 | | |
| | 139 | 27 | | foreach (var stone in stones) |
| | 56 | 28 | | { |
| | 56 | 29 | | unionFind.Union(stone[0], stone[1] + 10001); |
| | 56 | 30 | | } |
| | | 31 | | |
| | 9 | 32 | | return stones.Length - unionFind.ComponentCount; |
| | 9 | 33 | | } |
| | | 34 | | |
| | | 35 | | private class UnionFind |
| | | 36 | | { |
| | | 37 | | private readonly int[] _parent; |
| | 9 | 38 | | private readonly HashSet<int> _uniqueNodes = []; |
| | | 39 | | |
| | 9 | 40 | | public UnionFind(int n) |
| | 9 | 41 | | { |
| | 9 | 42 | | _parent = new int[n]; |
| | | 43 | | |
| | 9 | 44 | | Array.Fill(_parent, -1); |
| | 9 | 45 | | } |
| | | 46 | | |
| | 247 | 47 | | public int ComponentCount { get; private set; } |
| | | 48 | | |
| | | 49 | | private int Find(int node) |
| | 169 | 50 | | { |
| | 169 | 51 | | if (!_uniqueNodes.Contains(node)) |
| | 66 | 52 | | { |
| | 66 | 53 | | ComponentCount++; |
| | | 54 | | |
| | 66 | 55 | | _uniqueNodes.Add(node); |
| | 66 | 56 | | } |
| | | 57 | | |
| | 169 | 58 | | if (_parent[node] == -1) |
| | 112 | 59 | | { |
| | 112 | 60 | | return node; |
| | | 61 | | } |
| | | 62 | | |
| | 57 | 63 | | return _parent[node] = Find(_parent[node]); |
| | 169 | 64 | | } |
| | | 65 | | |
| | | 66 | | public void Union(int x, int y) |
| | 56 | 67 | | { |
| | 56 | 68 | | var rootX = Find(x); |
| | 56 | 69 | | var rootY = Find(y); |
| | | 70 | | |
| | 56 | 71 | | if (rootX == rootY) |
| | 3 | 72 | | { |
| | 3 | 73 | | return; |
| | | 74 | | } |
| | | 75 | | |
| | 53 | 76 | | _parent[rootX] = rootY; |
| | | 77 | | |
| | 53 | 78 | | ComponentCount--; |
| | 56 | 79 | | } |
| | | 80 | | } |
| | | 81 | | } |