| | | 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.CountSpecialTriplets; |
| | | 13 | | |
| | | 14 | | /// <inheritdoc /> |
| | | 15 | | public sealed class CountSpecialTripletsBruteForce : ICountSpecialTriplets |
| | | 16 | | { |
| | | 17 | | private const int Modulo = 1_000_000_007; |
| | | 18 | | |
| | | 19 | | /// <summary> |
| | | 20 | | /// Time complexity - O(n^3) |
| | | 21 | | /// Space complexity - O(1) |
| | | 22 | | /// </summary> |
| | | 23 | | /// <param name="nums"></param> |
| | | 24 | | /// <returns></returns> |
| | | 25 | | public int SpecialTriplets(int[] nums) |
| | 3 | 26 | | { |
| | 3 | 27 | | long result = 0; |
| | | 28 | | |
| | 3 | 29 | | var numsLength = nums.Length; |
| | | 30 | | |
| | 18 | 31 | | for (var i = 0; i < numsLength - 2; i++) |
| | 6 | 32 | | { |
| | 6 | 33 | | var a = nums[i]; |
| | | 34 | | |
| | 32 | 35 | | for (var j = i + 1; j < numsLength - 1; j++) |
| | 10 | 36 | | { |
| | 10 | 37 | | var b = nums[j] * 2; |
| | | 38 | | |
| | 10 | 39 | | if (a != b) |
| | 6 | 40 | | { |
| | 6 | 41 | | continue; |
| | | 42 | | } |
| | | 43 | | |
| | 22 | 44 | | for (var k = j + 1; k < numsLength; k++) |
| | 7 | 45 | | { |
| | 7 | 46 | | var c = nums[k]; |
| | | 47 | | |
| | 7 | 48 | | if (b != c) |
| | 3 | 49 | | { |
| | 3 | 50 | | continue; |
| | | 51 | | } |
| | | 52 | | |
| | 4 | 53 | | result++; |
| | | 54 | | |
| | 4 | 55 | | if (result == Modulo) |
| | 0 | 56 | | { |
| | 0 | 57 | | result = 0; |
| | 0 | 58 | | } |
| | 4 | 59 | | } |
| | 4 | 60 | | } |
| | 6 | 61 | | } |
| | | 62 | | |
| | 3 | 63 | | return (int)result; |
| | 3 | 64 | | } |
| | | 65 | | } |