CCF考试——201312-2ISBN号码

#include <iostream>
#include <string>
using namespace std;

string str;
long long sum;
int cnt;
int len;

int main()
{
    while(cin>>str){
        cnt = 1;
        sum = 0;
        len = str.length();
        for(int i = 0 ; i < len-1 ; i++){
            if(str[i] == '-'){
                continue;
            }else{
                sum += (str[i] - '0')*cnt;
                cnt++;
            }
        }
        sum %= 11;
        if(sum == 10 && str[len-1] == 'X'){
            cout<<"Right"<<endl;
        }else if(sum < 10 && sum == str[len-1]-'0'){
            cout<<"Right"<<endl;
        }else{
            str = str.substr(0,len-1);
            cout<<str;
            if(sum == 10){
                cout<<"X"<<endl;
            }else{
                cout<<sum<<endl;
            }
        }
    }

    return 0;
 }