如何让程序执行switch语句后继续循环？

[Kongbeiz]

#include"stdio.h"
int main(void)
{
char grade;
printf("Put char :\n");
scanf("%c",&grade);
switch (grade)
{
case 'A':printf("score is 85--100\n");break;
case 'B':printf("score is 70--85\n"); break;
case 'C':printf("score is 60--70\n"); break;
case 'D':printf("Failinggrade!\n");break;
default:printf("You are wrong!\n");
}
getch();
return 0;
}
如何在输入错误时（如：输入X），显示"You are wrong!",然后回车继续输入，直到输入正确为止？

[witwolf]

#include<stdio.h>
int main(void)
{
	char grade;
	A:
		printf("Put char :\n");
		scanf("%c",&grade);
		switch (grade)
		{
			case 'A':printf("score is 85--100\n");break;
			case 'B':printf("score is 70--85\n"); break;
			case 'C':printf("score is 60--70\n"); break;
			case 'D':printf("Failinggrade!\n");break;
			default:printf("You are wrong!\n");
				goto A;
		}
		getchar();
	return 0;
}

[Kongbeiz]

这样编译后，运行时如果输入错误，会显示两遍“You are wrong!”“Put char:”

[Kongbeiz]

谢谢提醒，终于解决了

[Kongbeiz]

#include"stdio.h"
int main(void)
{
char grade;
A:
printf("Put char :\n");
scanf("\n%c",&grade);
switch (grade)
{
case 'A':printf("score is 85--100\n");break;
case 'B':printf("score is 70--85\n"); break;
case 'C':printf("score is 60--70\n"); break;
case 'D':printf("Failinggrade!\n");break;
default:printf("You are wrong!\n");
goto A;
}
getch();
return 0;
}