poj 2641 Billiard

#include <iostream>#include <fstream>#include <algorithm>#include <cstring>#include <cmath>#include <climits>using namespace std;const double EPS=1e-6;const double PI=acos(-1.0);bool zero(double x){    return abs(x)<EPS;}inline double SQR(double x){    return x*x;}double a,b,s,m,n;int main(){    while(scanf("%lf %lf %lf %lf %lf",&a,&b,&s,&m,&n)!=EOF &&          (!zero(a) || !zero(b) || !zero(s) || !zero(m) || !zero(n)))    {        double v=sqrt(double(SQR(a*m)+SQR(b*n)))/s;        double ang=acos(a*m/(v*s))/PI*180;        printf("%0.2lf %0.2lfn",ang,v);    }    return 0;}