限制i在1~9
//无限循环
void main()
{
int i;
scanf("%d",&i);
while(i9)
{
printf("error,enter again:");
scanf("%d",&i);
}
}
//正常
void main()
{
int i,f;
if((f=scanf("%d",&i))!=1||i9)
{
if(f!=EOF)
while(getchar()!='\n');
printf("error,enter again:");
}