| | | 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.CheckIfNAndItsDoubleExist; |
| | | 13 | | |
| | | 14 | | /// <inheritdoc /> |
| | | 15 | | public class CheckIfNAndItsDoubleExistHashSet : ICheckIfNAndItsDoubleExist |
| | | 16 | | { |
| | | 17 | | /// <summary> |
| | | 18 | | /// Time complexity - O(n) |
| | | 19 | | /// Space complexity - O(n) |
| | | 20 | | /// </summary> |
| | | 21 | | /// <param name="arr"></param> |
| | | 22 | | /// <returns></returns> |
| | | 23 | | public bool CheckIfExist(int[] arr) |
| | 5 | 24 | | { |
| | 5 | 25 | | var hashSet = new HashSet<int>(); |
| | | 26 | | |
| | 50 | 27 | | foreach (var item in arr) |
| | 19 | 28 | | { |
| | 19 | 29 | | if (hashSet.Contains(item * 2) || (item % 2 == 0 && hashSet.Contains(item / 2))) |
| | 3 | 30 | | { |
| | 3 | 31 | | return true; |
| | | 32 | | } |
| | | 33 | | |
| | 16 | 34 | | hashSet.Add(item); |
| | 16 | 35 | | } |
| | | 36 | | |
| | 2 | 37 | | return false; |
| | 5 | 38 | | } |
| | | 39 | | } |