正常人都能看懂

#include<bits/stdc++.h>
using namespace std;
int main(){
string n;
int a = 0,b = 0,c = 0;
getline(cin,n);
for (int i = 0;n[i] != '?';i++){
if(n[i] >= 'a' && n[i] <= 'z'){
a++;
}
else if(n[i] >='0' && n[i] <='9'){
b++;
}
else{
c++;
}
}
cout << "Letters=" << a << endl;
cout << "Digits=" << b << endl;
cout << "Others=" << c << endl;
return 0;
}