题解 | #Primary Arithmetic#

#include <iostream>
using namespace std;

int main() {
    string x,y;
    while(cin>>x>>y && x!="0" && y!="0"){
        int x_len = x.size();
        int y_len = y.size();
        if(x_len < y_len) {
            swap(x,y);
            x_len=x.size();
            y_len=y.size();
        }
        int z = x_len - y_len;
        y.insert(0,z,'0');
        int cnt=0,mod=0;
        for(int i=x.size()-1;i>=0;i--){
            int tmp = x[i]-'0' + y[i]-'0' + mod;
            if(tmp > 9) cnt++;
            // cout<<cnt<<endl;
            mod = tmp / 10;
            // cout<<"mod:"<<mod<<endl;
        }
        if(cnt>1) cout<<cnt<<" carry operations."<<endl;
        else if(cnt==1) cout<<cnt<<" carry operation."<<endl;
        else cout<<"NO carry operation."<<endl;

    }
}
// 64 位输出请用 printf("%lld")