View Code of Problem 106

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

int main()
{
    float x1,y1,x2,y2,d,s,r,a;
    while(scanf("%f %f %f %f %f",&x1,&y1,&x2,&y2,&r) != EOF)
    {
        d = sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1));
        if(d == 0)
            printf("重合\n");
        if(d > 2*r)
            printf("相离\n");
        if(d == 2*r)
            printf("相切\n");
        if(d < 2*r&&d > 0)
        {
            printf("相交 ");
            a = acos(d/2*r);
            s = 2*r*r*a - d*r*sin(a);
            printf("%.2f\n",s);
        }
    }
    return 0;
}