View Code of Problem 106

#include<stdio.h>
#include<math.h>
int main()
{
	double x1,y1,x2,y2,r,s,d,area;
	while(scanf("%lf %lf %lf %lf %lf",&x1,&x2,&y1,&y2,&r)!=EOF)
	{
		area=0;
		s=sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
	     if(x1==x2&&y1==y2)
		  printf("重合\n");
		  else
		  {
		  	if(s==2*r)
		  	printf("相切\n");
		  	else if(s>2*r)
		  	printf("相离\n");
		  	else
		  	{
		  	   d=2*acos(s/(2*r));
			   area=r*r*d-r*r*sin(d); 
			   printf("相交 %0.2f\n",area); 
			}
		  }
	} 
		return 0;
}