| | | 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.MinimumIndexOfValidSplit; |
| | | 13 | | |
| | | 14 | | /// <inheritdoc /> |
| | | 15 | | public class MinimumIndexOfValidSplitDictionary : IMinimumIndexOfValidSplit |
| | | 16 | | { |
| | | 17 | | /// <summary> |
| | | 18 | | /// Time complexity - O(n) |
| | | 19 | | /// Space complexity - O(n) |
| | | 20 | | /// </summary> |
| | | 21 | | /// <param name="nums"></param> |
| | | 22 | | /// <returns></returns> |
| | | 23 | | public int MinimumIndex(IList<int> nums) |
| | 3 | 24 | | { |
| | 3 | 25 | | var frequencyDictionary = new Dictionary<int, int>(); |
| | 3 | 26 | | var dominant = nums[0]; |
| | 3 | 27 | | var dominantFreq = 0; |
| | | 28 | | |
| | 51 | 29 | | foreach (var num in nums) |
| | 21 | 30 | | { |
| | 21 | 31 | | frequencyDictionary[num] = frequencyDictionary.GetValueOrDefault(num) + 1; |
| | | 32 | | |
| | 21 | 33 | | if (frequencyDictionary[num] <= dominantFreq) |
| | 8 | 34 | | { |
| | 8 | 35 | | continue; |
| | | 36 | | } |
| | | 37 | | |
| | 13 | 38 | | dominant = num; |
| | 13 | 39 | | dominantFreq = frequencyDictionary[num]; |
| | 13 | 40 | | } |
| | | 41 | | |
| | 3 | 42 | | var leftDominantCount = 0; |
| | | 43 | | |
| | 30 | 44 | | for (var i = 0; i < nums.Count - 1; i++) |
| | 14 | 45 | | { |
| | 14 | 46 | | if (nums[i] == dominant) |
| | 9 | 47 | | { |
| | 9 | 48 | | leftDominantCount++; |
| | 9 | 49 | | } |
| | | 50 | | |
| | 14 | 51 | | var leftIsDominant = leftDominantCount * 2 > i + 1; |
| | 14 | 52 | | var rightIsDominant = (dominantFreq - leftDominantCount) * 2 > nums.Count - i - 1; |
| | | 53 | | |
| | 14 | 54 | | if (leftIsDominant && rightIsDominant) |
| | 2 | 55 | | { |
| | 2 | 56 | | return i; |
| | | 57 | | } |
| | 12 | 58 | | } |
| | | 59 | | |
| | 1 | 60 | | return -1; |
| | 3 | 61 | | } |
| | | 62 | | } |