题解 | #加减乘除#

#include <iostream>
using namespace std;

int main() {
    int a;
    while(cin>>a){
        getchar();
        char c;
        cin>>c;
        if(c=='+'){
            int b;
            cin>>b;
            cout<<a+b<<endl;
        }else if(c=='-'){
            int b;
            cin>>b;
            cout<<a-b<<endl;
        }else if(c=='*'){
            int b;
            cin>>b;
            cout<<a*b<<endl;
        }else if(c=='/'){
            int b;
            cin>>b;
            if(b==0) cout<<"error"<<endl;
            else cout<<a/b<<endl;
        }else if(c=='%'){
            int b;
            cin>>b;
            if(b==0) cout<<"error"<<endl;
            else cout<<a%b<<endl;
        }else{
            int res=1;
            for(int i=1;i<=a;i++) res*=i;
            cout<<res<<endl;
        }
    }
    return 0;
}