![#include<stdio.h>
int main(){
	float score;
	char grade;
	for(int i=0;i<7;i++){
	printf("请输入成绩：");
	scanf("%f",&score);
	while(score>100||score<0)
	{
		printf("\n输入的成绩有误，请重新输入：");
		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("成绩是%.1f对应的等级是%c\n",score,grade);
	}	return 0;
	
				
			
		
		
	}
	
](https://img-blog.csdnimg.cn/fd9ec7129b614869bf042eb770a3d2fb.png)