题解

#include<iostream>
using namespace std;
int main(){
    int Letters=0,Digits=0,Others=0;
    string a;
    getline(cin,a);
    for(int i=0;i<a.size()-1;i++){
        if(a[i]=='?')break;
        if(a[i]>='a'&&a[i]<='z')Letters++;
        else if(a[i]>='0'&&a[i]<='9')Digits++;
        else Others++;
    }cout<<"Letters="<<Letters<<"\n"<<"Digits="<<Digits<<"\n"<<"Others="<<Others;
    return 0;
}

注意:如果用string类型，输入要用getline函数，否则会WA