1549.cpp

// Ivan Carvalho
// Solution to https://www.beecrowd.com.br/judge/problems/view/1549
#include <cmath>
#include <cstdio>
const double PI = acos(-1.0);
const double EPS = 1e-4;
int main() {
    int TC;
    scanf("%d", &TC);
    while (TC--) {
        int n, cap;
        double ini, fim, meio, resp, r, R, altura;
        scanf("%d %d", &n, &cap);
        scanf("%lf %lf %lf", &r, &R, &altura);
        ini = 0.0;
        fim = altura;
        while (fim - ini > EPS) {
            meio = (ini + fim) * 0.5;
            double B = r + ((R - r) / altura) * meio;
            double volume = PI * meio * (B * B + B * r + r * r) / 3.0;
            if (n * volume >= cap) {
                resp = meio;
                fim = meio - EPS;
            } else
                ini = meio + EPS;
        }
        printf("%.2lf\n", resp);
    }
    return 0;
}