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’，80～89分为‘B’，70～79分为‘C’，60～69为‘D’，60分以下为‘E’。

#include <stdio.h>
int main()
{
 	int score; 
 	printf("Please enter score:");
 	scanf("%d",&score);
 	if(score<0||score>100)  
	 	printf("Input error!\n"); 
	else 
	{
	    mark=score/10;
	    switch (mark)    
	    {
		      case 10:
		      case 9:  printf("%d--A\n",score); break;
		      case 8:  printf("%d--B\n",score); break;
		      case 7:  printf("%d--C\n",score); break;
		      case 6:  printf("%d--D\n",score); break;
		      case 5:
		      case 4:
		      case 3:
		      case 2:
		      case 1:
		      case 0:  printf("%d--E\n",score); break;
	    }
	}
	return 0;
}