【lamda表达式】451. 根据字符出现频率排序

class Solution {
public:
    string frequencySort(string s) {
        int dict_s[300];
        memset(dict_s, 0, sizeof(dict_s));
        for(auto ch : s)
            dict_s[ch] ++;
        sort(s.begin(), s.end(), [dict_s](auto a, auto b){
            return dict_s[a] > dict_s[b] || (dict_s[a] == dict_s[b] && a < b);
        });
        return s;
    }
};