Submission #1388154

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Source Code Expand

#include <bits/stdc++.h>
#include <iomanip>
using namespace std;

typedef long long LL;
typedef long double LD;

LD calc(int n, LD d1, LD d) {
	if (n == 1) {
		return d1 + d / 2;
	}
	return d1 + (n * 2 - 1) * d / 2 + calc(n - 1, d1 + (2 * d1 + 5 * d) / n / 2, d + d * 2 / n);
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	
	int n;
	LD d1, x;
	cin >> n >> d1 >> x;
	cout << fixed << setprecision(10) << calc(n, d1, x) << endl;
}

Submission Info

Judge Result