| | | 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 | | using System.Text; |
| | | 13 | | |
| | | 14 | | namespace LeetCode.Algorithms.MajorityFrequencyCharacters; |
| | | 15 | | |
| | | 16 | | /// <inheritdoc /> |
| | | 17 | | public sealed class MajorityFrequencyCharactersFrequencyDictionary : IMajorityFrequencyCharacters |
| | | 18 | | { |
| | | 19 | | /// <summary> |
| | | 20 | | /// Time complexity - O(n) |
| | | 21 | | /// Space complexity - O(n) |
| | | 22 | | /// </summary> |
| | | 23 | | /// <param name="s"></param> |
| | | 24 | | /// <returns></returns> |
| | | 25 | | public string MajorityFrequencyGroup(string s) |
| | 3 | 26 | | { |
| | 3 | 27 | | var characterToFrequencyDictionary = new Dictionary<char, int>(); |
| | | 28 | | |
| | 55 | 29 | | foreach (var c in s) |
| | 23 | 30 | | { |
| | 23 | 31 | | if (!characterToFrequencyDictionary.TryAdd(c, 1)) |
| | 10 | 32 | | { |
| | 10 | 33 | | characterToFrequencyDictionary[c]++; |
| | 10 | 34 | | } |
| | 23 | 35 | | } |
| | | 36 | | |
| | 3 | 37 | | var maxFrequency = 0; |
| | 3 | 38 | | var maxSize = 0; |
| | | 39 | | |
| | 3 | 40 | | var frequencyToSizeDictionary = new Dictionary<int, int>(); |
| | | 41 | | |
| | 35 | 42 | | foreach (var (_, frequency) in characterToFrequencyDictionary) |
| | 13 | 43 | | { |
| | 13 | 44 | | if (!frequencyToSizeDictionary.TryAdd(frequency, 1)) |
| | 6 | 45 | | { |
| | 6 | 46 | | frequencyToSizeDictionary[frequency]++; |
| | 6 | 47 | | } |
| | | 48 | | |
| | 13 | 49 | | var size = frequencyToSizeDictionary[frequency]; |
| | | 50 | | |
| | 13 | 51 | | if (size < maxSize) |
| | 4 | 52 | | { |
| | 4 | 53 | | continue; |
| | | 54 | | } |
| | | 55 | | |
| | 9 | 56 | | if (size == maxSize && frequency <= maxFrequency) |
| | 1 | 57 | | { |
| | 1 | 58 | | continue; |
| | | 59 | | } |
| | | 60 | | |
| | 8 | 61 | | maxFrequency = frequency; |
| | 8 | 62 | | maxSize = size; |
| | 8 | 63 | | } |
| | | 64 | | |
| | 3 | 65 | | var resultStringBuilder = new StringBuilder(); |
| | | 66 | | |
| | 35 | 67 | | foreach (var (character, frequency) in characterToFrequencyDictionary) |
| | 13 | 68 | | { |
| | 13 | 69 | | if (frequency == maxFrequency) |
| | 8 | 70 | | { |
| | 8 | 71 | | resultStringBuilder.Append(character); |
| | 8 | 72 | | } |
| | 13 | 73 | | } |
| | | 74 | | |
| | 3 | 75 | | return resultStringBuilder.ToString(); |
| | 3 | 76 | | } |
| | | 77 | | } |