| | | 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 | | namespace LeetCode.Algorithms.SmallestNumberWithAllSetBits; |
| | | 13 | | |
| | | 14 | | /// <inheritdoc /> |
| | | 15 | | public sealed class SmallestNumberWithAllSetBitsBinarySearch : ISmallestNumberWithAllSetBits |
| | | 16 | | { |
| | 1 | 17 | | private static readonly int[] Numbers = |
| | 1 | 18 | | [ |
| | 1 | 19 | | 3, |
| | 1 | 20 | | 7, |
| | 1 | 21 | | 15, |
| | 1 | 22 | | 31, |
| | 1 | 23 | | 63, |
| | 1 | 24 | | 127, |
| | 1 | 25 | | 255, |
| | 1 | 26 | | 511, |
| | 1 | 27 | | 1023 |
| | 1 | 28 | | ]; |
| | | 29 | | |
| | | 30 | | /// <summary> |
| | | 31 | | /// Time complexity - O(log n) |
| | | 32 | | /// Space complexity - O(1) |
| | | 33 | | /// </summary> |
| | | 34 | | /// <param name="n"></param> |
| | | 35 | | /// <returns></returns> |
| | | 36 | | public int SmallestNumber(int n) |
| | 3 | 37 | | { |
| | 3 | 38 | | if (n == 1) |
| | 0 | 39 | | { |
| | 0 | 40 | | return 1; |
| | | 41 | | } |
| | | 42 | | |
| | 3 | 43 | | var index = Array.BinarySearch(Numbers, n); |
| | | 44 | | |
| | 3 | 45 | | if (index >= 0) |
| | 1 | 46 | | { |
| | 1 | 47 | | return Numbers[index]; |
| | | 48 | | } |
| | | 49 | | |
| | 2 | 50 | | index = ~index; |
| | | 51 | | |
| | 2 | 52 | | return index < Numbers.Length ? Numbers[index] : Numbers[^1]; |
| | 3 | 53 | | } |
| | | 54 | | } |