C语言实现计算成绩分数所在等级

C语言实现计算成绩分数所在等级
给出一百分制成绩，要求输出成绩等级’A’、’B’、’C’、’D’、’E’。90分以上为‘A’,8089为‘B’,7079为‘C’,60~69为‘D’, 60分以下为‘E’。

#include  "stdio.h"
int main() 
{
	float score;
	char grade;
	scanf("%f",&score);
	switch((int)(score/10)) {
		case 10:
		case 9:
			grade='A';
			break;
		case 8:
			grade='B';
			break;
		case 7:
			grade='C';
			break;
		case 6:
			grade='D';
			break;
		case 5:
		case 4:
		case 3:
		case 2:
		case 1:
		case 0:
			grade='E';
	}
	printf("%c\n ",grade);
	return 0;
}

#include "stdio.h"
int main() {
// your code
      int grade;
    scanf("%d",&grade);
    switch (grade)
    {
    case 90 ... 100:
        printf("A");
        break;
    case 80 ... 89:
        printf("B");
        break;
    case 70 ... 79:
        printf("C");
        break;
    case 60 ... 69:
        printf("D");
        break;
    default:
        printf("E");
        break;
    }
  
}