分数转换-水晕

#include<stdio.h>
int main()
{
int N,i,j,core,n;
scanf("%d",&N);
printf("请输入学生成绩分数：\n");
while(N--)
{
scanf("%d",&j);
core=j/10;
switch(core)
{
case 10:;
case 9:   printf("等级为A\n");break;
case 8:   printf("等级为B\n");break;
case 7:   printf("等级为C\n");break;
case 6:   printf("等级为D\n");break;
default:  printf("等级为E\n");break;
}
}
}