题解 | #计算某字符出现次数#

#include <cctype>
#include <iostream>
#include <algorithm>
using namespace std;

int main(){
    string input;
    char ch;
    getline(cin, input);
    cin >> ch;
    ch = tolower(ch);
    transform(input.begin(), input.end(), input.begin(), [](unsigned char c){
        return tolower(c);
    });
    int counts = count(input.begin(), input.end(), ch);
    cout << counts << endl;
    return 0;
}