hdu2289 Cup

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=2289

#include <stdio.h>#include <math.h>#define EPS 1e-8const double PI=3.14159265;double r,R,H,V;double Cal(double x){double r0=(R-r)*x/H+r;return PI*x*(r*r+r0*r0+r*r0)/3.0;}int main(){int test;double left,right,mid;scanf("%d",&test);while(test--){scanf("%lf %lf %lf %lf",&r,&R,&H,&V);left=0.0,right=H;while(right-left>EPS){mid=(right+left)/2.0;if(Cal(mid)-V>EPS)right=mid;elseleft=mid;}printf("%.6lf\n",mid);}return 0;}