단계별로 풀어보기 - 조건문 - 2단계
https://www.acmicpc.net/problem/9498
#include <iostream>
using namespace std;
int main()
{
int score;
cin>>score;
if((score<=100)&&(score>=90))
{
cout<<"A";
}
else if((score<90)&&(score>=80))
{
cout<<"B";
}
else if((score<80)&&(score>=70))
{
cout<<"C";
}
else if((score<70)&&(score>=60))
{
cout<<"D";
}
else
{
cout<<"F";
}
return 0;
}