题解

#include<bits/stdc++.h>  //桶排序哦~
using namespace std;
int main(){
    string str;
    int b[28] = {};
    getline (cin ,str);
    for (int i = 0 ; i < str.size() ; i++){
        b[int(struct[i]) - 96]++;  //a~z范围减96变成1~27
    }
    for (int i = 0 ; i <= 27 ; i++){
    	if (b[i] != 0)
        	cout << char(i + 96) << ":" << b[i] << "\n";  //再加回去，输出字母
    }
    return 0;
}