杭电 hdu 2004

成绩转换：

#include<iostream>
using namespace std;
int main(){
    int score;
    while(cin>>score){
        if(score<=59&&score>=0)
            cout<<"E"<<endl;
        else{
            if(score>=60&&score<=69)
                cout<<"D"<<endl;
            else{
                if(score>=70&&score<=79)
                    cout<<"C"<<endl;
                else{
                    if(score>=80&&score<=89)
                        cout<<"B"<<endl;
                    else{
                        if(score>=90&&score<=100)
                            cout<<"A"<<endl;
                        else
                            cout<<"Score is error!"<<endl;
                    }
                }
            }
        }
    }
    return 0;
}