题解 | #游游开车出游#

#include "bits/stdc++.h"

using namespace std;
#define int long long
#define pb push_back
#define endl "\n"
#define x first
#define y second
#define PII pair<int,int>
#define PIII pair<int,PII>
const int MOD = 1e9 + 7;
const int N = 3e5;

void slu() {
    double v, x, y;
    cin >> v >> x >> y;
    double cost = (2.0 * pow(x, 0.5) * pow(y, 0.5) - v) / x;
    if (cost - 0 < 0.0000000001 || (v != 0 && cost - y / v > 0.0000001) ||
        (pow(x, 0.5) * pow(y, 0.5) - v < 0.000000001))
        cost = y / v;
    cout << fixed << setprecision(14) << cost;
}

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int T;
//    cin >> T;
    T = 1;
    while (T--)slu();

}