View Code of Problem 106

#include<stdio.h>
#include<math.h>

int main(){
	double x1,x2,y1,y2,d,s,r,m;
	
	while(scanf("%lf%lf%lf%lf%lf",&x1,&y1,&x2,&y2,&r)!=EOF)
	{
		m=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));
			   m=r*r*d-r*r*sin(d); 
			   printf("相交 %0.2f\n",m); 
			}
		}
	}		
	return 0;
}