题解

#include<iostream>
using namespace std;
int main(){
	char a;
	int i,k=0,m=0,n=0;
	while(a=getchar(),a!='?'){
		if(a>='0'&&a<='9'){
            k++;
        }
		else if((a>='A'&&a<='Z')||(a>='a'&&a<='z')){
        	m++;
        }
		else{
            n++;
        } 
	}
	cout<<"Letters="<<m<<endl<<"Digits="<<k<<endl<<"Others="<<n<<endl;
	return 0;
}