L3-013 非常弹的球

初速度:$v = \sqrt{\cfrac{2 * E}{m}};$
竖直速度:$v_y = v \,sin(ans) = g * t$
水平距离:$s = v_x * 2t = v \, cos(ans) * 2t = \cfrac{2Esin(2ans)}{mg}$

#include <bits/stdc++.h>

using namespace std;

int main() {
    double m, g = 9.8, p;
    cin >> m >> p;
    m = m / 100.0;
    double s = 1e9;
    double res = 0;
    double E = 1000.0;
    while (s > 1e-8) {
        res += (s = 2 * E / (m * g));
        E = E - (E * (p / 100.0));      
    }
    cout << fixed << setprecision(3) << res << "\n";

    return 0;
}