c语言输出有问题

#include "stdio.h"
void main()
{
int grades,c;
printf("ÇëÊäÈëÒ»¸ö°Ù·ÖÊý³É¼¨:\n");
scanf("%d",&grades); //zheli
c=grades/10;
printf("µÈ¼¶Îª£º\n");
switch(c)
{
case 10:
case 9: printf("A\n");break;
case 8: printf("B\n");break;
case 7: printf("C\n");break;
case 6: printf("D\n");break;
default:printf("E\n");
}
}

scanf("%d",&grades); 不是d%

#include "stdio.h"
main()
{
int grades,c;
printf("请输入一个百分数成绩:\n");
scanf("%d",&grades);
c=grades/10;
printf("等级为：\n");
switch(c)
{
case 10:
ca