Submission #1591387

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Source Code Expand

#include <iostream>
#include <vector>
#include <iomanip>

int main() {
	int n;
	std::cin >> n;

	std::vector<int> coins(n);
	for (auto&& e : coins)
		std::cin >> e;

	double ans = 0;
	for (int i = 0; i < coins.size(); ++i) {
		int numDivisor = 0;
		for (int j = 0; j < coins.size(); ++j) {
			if (j == i)
				continue;

			if (coins[i] % coins[j] == 0)
				++numDivisor;
		}

		if (numDivisor % 2 == 0)
			ans += (numDivisor + 2) / static_cast<double>(numDivisor * 2 + 2);
		else
			ans += 0.5;
	}

	std::cout << std::setprecision(8) << ans << std::endl;
}

Submission Info

Judge Result