HDU2004 成绩转换

#include <iostream>
#include <cstdio>
#include <cmath>

using namespace std;
int main()
{
	int score;
	while(cin >> score)
	{
		if(score<0 || score>100)
		{
			cout << "Score is error!"<<endl;
			continue;
		}
		switch(score/10)
		{
		case 10:
		case 9:
			cout<< "A" <<endl;
			break;
		case 8:
			cout << "B" <<endl;
			break;
		case 7:
			cout<< "C" <<endl;
			break;
		case 6:
			cout << "D" <<endl;
			break;
		default:
			cout << "E" <<endl;
			break;
		}
	}
	return 0;
}