| | | 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.MinimizeMaximumPairSumInArray; |
| | | 13 | | |
| | | 14 | | /// <inheritdoc /> |
| | | 15 | | public sealed class MinimizeMaximumPairSumInArrayCounting : IMinimizeMaximumPairSumInArray |
| | | 16 | | { |
| | | 17 | | private const int MaxValue = 100_000; |
| | | 18 | | |
| | | 19 | | /// <summary> |
| | | 20 | | /// Time complexity - O(n) |
| | | 21 | | /// Space complexity - O() |
| | | 22 | | /// </summary> |
| | | 23 | | /// <param name="nums"></param> |
| | | 24 | | /// <returns></returns> |
| | | 25 | | public int MinPairSum(int[] nums) |
| | 2 | 26 | | { |
| | 2 | 27 | | Span<int> frequencies = stackalloc int[MaxValue + 1]; |
| | | 28 | | |
| | 26 | 29 | | foreach (var num in nums) |
| | 10 | 30 | | { |
| | 10 | 31 | | frequencies[num]++; |
| | 10 | 32 | | } |
| | | 33 | | |
| | 2 | 34 | | var left = 1; |
| | 2 | 35 | | var right = MaxValue; |
| | | 36 | | |
| | 2 | 37 | | var result = 0; |
| | | 38 | | |
| | 2 | 39 | | var remaining = nums.Length; |
| | | 40 | | |
| | 7 | 41 | | while (remaining > 0) |
| | 5 | 42 | | { |
| | 10 | 43 | | while (left <= right && frequencies[left] == 0) |
| | 5 | 44 | | { |
| | 5 | 45 | | left++; |
| | 5 | 46 | | } |
| | | 47 | | |
| | 199998 | 48 | | while (left <= right && frequencies[right] == 0) |
| | 199993 | 49 | | { |
| | 199993 | 50 | | right--; |
| | 199993 | 51 | | } |
| | | 52 | | |
| | 5 | 53 | | var sum = left + right; |
| | | 54 | | |
| | 5 | 55 | | result = Math.Max(result, sum); |
| | | 56 | | |
| | 5 | 57 | | frequencies[left]--; |
| | 5 | 58 | | frequencies[right]--; |
| | | 59 | | |
| | 5 | 60 | | remaining -= 2; |
| | 5 | 61 | | } |
| | | 62 | | |
| | 2 | 63 | | return result; |
| | 2 | 64 | | } |
| | | 65 | | } |