2-9

#include <stdio.h>
int main()
{
  double x,y,d;
  char ch;
 do
 {
  scanf("%lf %lf",&x,&y);
  d=(x-2)*(x-2)+(y-2)*(y-2);
  if(d>1)
 printf("A点在圆外\n");
  else if(d>0&&d!=1)
printf("A点在圆内\n");
  else
printf("A点在圆上\n");
  printf("是否继续？[y/n]");
 while((ch=getchar())!='\n');
 }
while((ch=getchar())=='y'||ch=='\n');
  return 0;

}