c++ - 查找单个字符串中重复次数最多和次多的字符

Question

我能找到重复次数最多的字符，但我找不到第二多重复的字符

我不明白找到第二个最重复的字符的逻辑

void most_frequent_letter(string str, struct frequents result[])



    int len = str.length();

    int max = 0, i = 0, k = 0, Secmax = 0, m = 0;

for (i = 0 ; i <= len; ++i)
{
    if (str[i] >= 48 && str[i] <= 57)
    {
        result[0].count = 0;
        break;
    }
    if(str[i] >= 65 && str[i] <= 90)
    {
        str[i] += 32;

    }
    result[i].letter = str[i];
    result[i].count++;

    if (result[i].count > max && result[i].letter != ' ')
    {
        max = result[i].count;
        result[0].count = result[i].count;
        result[0].letter = str[i];

    }


}
cout << result[0].letter << endl;

Answer 1

这是一个运行良好的示例，如果您愿意，可以对其进行优化。

#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <map>
#include <iterator>

void find_most_repeated(std::string strData)
{
    std::map<char, int> mChars;

    for (int i = 0; i < strData.size(); i++)
        mChars[strData[i]] ++;

    std::vector<std::pair<char, int>> v{ std::make_move_iterator(begin(mChars)), std::make_move_iterator(end(mChars)) };

    std::sort(begin(v), end(v), 
        [](const std::pair<char, int>&  p1, const std::pair<char, int>&  p2) {return p1.second > p2.second; });

    std::cout << v[0].first << " " << v[1].first << std::endl;
}

int main()
{
    find_most_repeated(std::string("asdaaaasssaaaaa"));
}