| | | 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.TrionicArray1; |
| | | 13 | | |
| | | 14 | | /// <inheritdoc /> |
| | | 15 | | public class TrionicArray1Iterative : ITrionicArray1 |
| | | 16 | | { |
| | | 17 | | /// <summary> |
| | | 18 | | /// Time complexity - O(n) |
| | | 19 | | /// Space complexity - O(1) |
| | | 20 | | /// </summary> |
| | | 21 | | /// <param name="nums"></param> |
| | | 22 | | /// <returns></returns> |
| | | 23 | | public bool IsTrionic(int[] nums) |
| | 2 | 24 | | { |
| | 2 | 25 | | var n = nums.Length; |
| | | 26 | | |
| | 2 | 27 | | if (n < 4) |
| | 1 | 28 | | { |
| | 1 | 29 | | return false; |
| | | 30 | | } |
| | | 31 | | |
| | 1 | 32 | | var i = 1; |
| | | 33 | | |
| | 3 | 34 | | while (i < n && nums[i - 1] < nums[i]) |
| | 2 | 35 | | { |
| | 2 | 36 | | i++; |
| | 2 | 37 | | } |
| | | 38 | | |
| | 1 | 39 | | if (i < 2) |
| | 0 | 40 | | { |
| | 0 | 41 | | return false; |
| | | 42 | | } |
| | | 43 | | |
| | 1 | 44 | | if (i == n) |
| | 0 | 45 | | { |
| | 0 | 46 | | return false; |
| | | 47 | | } |
| | | 48 | | |
| | 1 | 49 | | var p = i; |
| | | 50 | | |
| | 3 | 51 | | while (p < n && nums[p - 1] > nums[p]) |
| | 2 | 52 | | { |
| | 2 | 53 | | p++; |
| | 2 | 54 | | } |
| | | 55 | | |
| | 1 | 56 | | if (p == i) |
| | 0 | 57 | | { |
| | 0 | 58 | | return false; |
| | | 59 | | } |
| | | 60 | | |
| | 1 | 61 | | if (p == n) |
| | 0 | 62 | | { |
| | 0 | 63 | | return false; |
| | | 64 | | } |
| | | 65 | | |
| | 1 | 66 | | var q = p; |
| | | 67 | | |
| | 2 | 68 | | while (q < n && nums[q - 1] < nums[q]) |
| | 1 | 69 | | { |
| | 1 | 70 | | q++; |
| | 1 | 71 | | } |
| | | 72 | | |
| | 1 | 73 | | return q == n && q > p; |
| | 2 | 74 | | } |
| | | 75 | | } |