View Code of Problem 106

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