[C++]백준 9498번:시험 성적

https://www.acmicpc.net/problem/9498

#include <iostream>

#include <string>

using namespace std;

int main() {

int score;

string grade;

while (true) {

cin >> score;

if (score >= 0 && score <= 100)

break;

}

if (score >= 90) grade = 'A';

else if (score >= 80) grade = 'B';

else if (score >= 70) grade = 'C';

else if (score >= 60) grade = 'D';

else grade = 'F';

cout << grade;

}