poj 2508 Conic distance

#include<cstdio>#include<cstring>#include<algorithm>#include<cmath>using namespace std;const double eps=1e-8,PI=acos(-1.0);int main(){    double r,h,l,p1,p2,th1,th2,dt;    while(scanf("%lf%lf%lf%lf%lf%lf",&r,&h,&p1,&th1,&p2,&th2)!=EOF)    {        dt=fabs((th1-th2)/180.0)*PI;        while(dt>2*PI+eps) dt-=2*PI;        if(dt>PI+eps) dt=2*PI-dt;        l=sqrt(h*h+r*r);        printf("%.2lfn",sqrt(p1*p1+p2*p2-2.0*p1*p2*cos(dt*r/l)));    }    return 0;}