题解 | 标题统计

#include <iostream>
using namespace std;

int main() {
    string s;
    getline(cin,s);
    int sum = 0;
    for(int i = 0;i<s.size();++i){
        if((s[i]>=48 &&s[i]<=57)||(s[i]>=65 && s[i]<=90) || (s[i]>=97 &&s[i]<=122)){
            sum++;
        }
    }
    cout << sum;
}