题解 | #统计字符#

#include <iostream>
using namespace std;

int main() {
    string str;
    getline(cin, str);
    // a英文字母,b空格,c数字,d其他
    int a = 0, b = 0, c = 0, d = 0;
    for (char ch:str){
        if (isalpha(ch)){
            ++a;
        }else{
            if (ch == ' '){
                ++b;
            }else{
                if (isdigit(ch)){
                    ++c;
                }else{
                    ++d;
                }
            }
        }
    }
    cout << a << endl << b << endl << c << endl << d << endl;
}