| | | 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.FindKthSmallestPairDistance; |
| | | 13 | | |
| | | 14 | | /// <inheritdoc /> |
| | | 15 | | public class FindKthSmallestPairDistanceBinarySearchWithSlidingWindow : IFindKthSmallestPairDistance |
| | | 16 | | { |
| | | 17 | | /// <summary> |
| | | 18 | | /// Time complexity - O(n log n + n log (max(nums))) |
| | | 19 | | /// Space complexity - O(1) |
| | | 20 | | /// </summary> |
| | | 21 | | /// <param name="nums"></param> |
| | | 22 | | /// <param name="k"></param> |
| | | 23 | | /// <returns></returns> |
| | | 24 | | public int SmallestDistancePair(int[] nums, int k) |
| | 3 | 25 | | { |
| | 3 | 26 | | Array.Sort(nums); |
| | | 27 | | |
| | 3 | 28 | | var left = 0; |
| | 3 | 29 | | var right = nums[^1] - nums[0]; |
| | | 30 | | |
| | 7 | 31 | | while (left < right) |
| | 4 | 32 | | { |
| | 4 | 33 | | var mid = left + ((right - left) / 2); |
| | 4 | 34 | | var count = CountPairsWithDistanceLessOrEqual(nums, mid); |
| | | 35 | | |
| | 4 | 36 | | if (count >= k) |
| | 2 | 37 | | { |
| | 2 | 38 | | right = mid; |
| | 2 | 39 | | } |
| | | 40 | | else |
| | 2 | 41 | | { |
| | 2 | 42 | | left = mid + 1; |
| | 2 | 43 | | } |
| | 4 | 44 | | } |
| | | 45 | | |
| | 3 | 46 | | return left; |
| | 3 | 47 | | } |
| | | 48 | | |
| | | 49 | | private static int CountPairsWithDistanceLessOrEqual(IReadOnlyList<int> nums, int target) |
| | 4 | 50 | | { |
| | 4 | 51 | | var count = 0; |
| | 4 | 52 | | var left = 0; |
| | | 53 | | |
| | 24 | 54 | | for (var right = 1; right < nums.Count; right++) |
| | 8 | 55 | | { |
| | 16 | 56 | | while (nums[right] - nums[left] > target) |
| | 8 | 57 | | { |
| | 8 | 58 | | left++; |
| | 8 | 59 | | } |
| | | 60 | | |
| | 8 | 61 | | count += right - left; |
| | 8 | 62 | | } |
| | | 63 | | |
| | 4 | 64 | | return count; |
| | 4 | 65 | | } |
| | | 66 | | } |