| | | 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.MaximizeExpressionOfThreeElements; |
| | | 13 | | |
| | | 14 | | /// <inheritdoc /> |
| | | 15 | | public sealed class MaximizeExpressionOfThreeElementsFrequencyArray : IMaximizeExpressionOfThreeElements |
| | | 16 | | { |
| | | 17 | | private const int Offset = 100; |
| | | 18 | | private const int Size = 201; |
| | | 19 | | |
| | | 20 | | /// <summary> |
| | | 21 | | /// Time complexity - O(n) |
| | | 22 | | /// Space complexity - O(1) |
| | | 23 | | /// </summary> |
| | | 24 | | /// <param name="nums"></param> |
| | | 25 | | /// <returns></returns> |
| | | 26 | | public int MaximizeExpressionOfThree(int[] nums) |
| | 2 | 27 | | { |
| | 2 | 28 | | Span<int> numsFrequencies = stackalloc int[Size]; |
| | | 29 | | |
| | 22 | 30 | | for (var i = 0; i < nums.Length; i++) |
| | 9 | 31 | | { |
| | 9 | 32 | | var num = nums[i]; |
| | | 33 | | |
| | 9 | 34 | | var index = GetIndex(num); |
| | | 35 | | |
| | 9 | 36 | | numsFrequencies[index]++; |
| | 9 | 37 | | } |
| | | 38 | | |
| | 2 | 39 | | var smallest = 0; |
| | | 40 | | |
| | 402 | 41 | | for (var i = 0; i < numsFrequencies.Length; i++) |
| | 201 | 42 | | { |
| | 201 | 43 | | if (numsFrequencies[i] <= 0) |
| | 199 | 44 | | { |
| | 199 | 45 | | continue; |
| | | 46 | | } |
| | | 47 | | |
| | 2 | 48 | | smallest = GetValue(i); |
| | | 49 | | |
| | 2 | 50 | | break; |
| | | 51 | | } |
| | | 52 | | |
| | 2 | 53 | | var firstFound = false; |
| | 2 | 54 | | var largest = 0; |
| | | 55 | | |
| | 388 | 56 | | for (var i = numsFrequencies.Length - 1; i >= 0; i--) |
| | 194 | 57 | | { |
| | 196 | 58 | | while (numsFrequencies[i] > 0) |
| | 4 | 59 | | { |
| | 4 | 60 | | var value = GetValue(i); |
| | | 61 | | |
| | 4 | 62 | | if (firstFound) |
| | 2 | 63 | | { |
| | 2 | 64 | | return largest + value - smallest; |
| | | 65 | | } |
| | | 66 | | |
| | 2 | 67 | | largest = value; |
| | | 68 | | |
| | 2 | 69 | | firstFound = true; |
| | | 70 | | |
| | 2 | 71 | | numsFrequencies[i]--; |
| | 2 | 72 | | } |
| | 192 | 73 | | } |
| | | 74 | | |
| | 0 | 75 | | return 0; |
| | 2 | 76 | | } |
| | | 77 | | |
| | | 78 | | private static int GetValue(int index) |
| | 6 | 79 | | { |
| | 6 | 80 | | return index - Offset; |
| | 6 | 81 | | } |
| | | 82 | | |
| | | 83 | | private static int GetIndex(int value) |
| | 9 | 84 | | { |
| | 9 | 85 | | return value + Offset; |
| | 9 | 86 | | } |
| | | 87 | | } |