| | | 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.FindKthBitInNthBinaryString; |
| | | 13 | | |
| | | 14 | | /// <inheritdoc /> |
| | | 15 | | public class FindKthBitInNthBinaryStringRecursive : IFindKthBitInNthBinaryString |
| | | 16 | | { |
| | | 17 | | /// <summary> |
| | | 18 | | /// Time complexity - O(n) |
| | | 19 | | /// Space complexity - O(n) |
| | | 20 | | /// </summary> |
| | | 21 | | /// <param name="n"></param> |
| | | 22 | | /// <param name="k"></param> |
| | | 23 | | /// <returns></returns> |
| | | 24 | | public char FindKthBit(int n, int k) |
| | 7 | 25 | | { |
| | 7 | 26 | | if (n == 1) |
| | 2 | 27 | | { |
| | 2 | 28 | | return '0'; |
| | | 29 | | } |
| | | 30 | | |
| | 5 | 31 | | var length = (1 << n) - 1; |
| | 5 | 32 | | var mid = (length / 2) + 1; |
| | | 33 | | |
| | 5 | 34 | | if (k == mid) |
| | 0 | 35 | | { |
| | 0 | 36 | | return '1'; |
| | | 37 | | } |
| | | 38 | | |
| | 5 | 39 | | if (k < mid) |
| | 2 | 40 | | { |
| | 2 | 41 | | return FindKthBit(n - 1, k); |
| | | 42 | | } |
| | | 43 | | |
| | 3 | 44 | | var mirroredIndex = length - k + 1; |
| | 3 | 45 | | var mirroredBit = FindKthBit(n - 1, mirroredIndex); |
| | | 46 | | |
| | 3 | 47 | | return mirroredBit == '0' ? '1' : '0'; |
| | 7 | 48 | | } |
| | | 49 | | } |