2529.cpp

HDOJ2501-2681acm解题报告

/*
H=h+l*tana-g*l^2/(2*v^2*cos^2a)  
tana=v^2/(g*l)
注：a为初速度与水平方向的分速度的夹角*/
#include<iostream>
#include<math.h>
using namespace std;
int main()
{
	double v,h,l,a,res,k,j;
	while(scanf("%lf%lf%lf",&h,&l,&v)&&(h||l||v))
	{
		a = atan(v*v/9.8/l);
		j=tan(a);
		k=atan(1);
		res = h+l*tan(a)-9.8*l*l/(2*v*v*cos(a)*cos(a));
		printf("%.2lf\n",res);
	}
}