#include‹stdio.h>
int main)
{
int grade;
print("请输入学生的成绩:");
scanf("d\n",&grade);
switch(grade/10)
{
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");
break;
return 0;
scanf("d\n",&grade); 改为
scanf("%d\n",&grade);