题解 | #计算某字符出现次数#

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

class TargetEqual
{
    public:
        TargetEqual(char ch):target(toupper(ch)){

        };
    

    bool operator()(char ch){
        return (toupper(ch) == toupper(target));
    }

    private:
        char target;
    
};

int main() {
    
    
    string line;
    getline(cin, line);
    char ch;
    cin >>ch;

    int count = std::count_if(line.begin(), line.end(), 
    TargetEqual(ch));
    std::cout << count;
}
// 64 位输出请用 printf("%lld")