範例程式碼 uva10056

//uva10056
#include <iostream>
#include <math.h>
#include <iomanip>
using namespace std;

int main() {
	int num;
	cin >> num;
	for (int i = 0; i < num; i++) {
		int player_num, player_n;
		double prob;
		cin >> player_num >> prob >> player_n;
		double q = 1 - prob;
		double second = pow(q, player_num);
		if (second == 1) {
			cout << "0.0000" << endl;
			continue;
		}
		double ans = prob * pow(q, player_n - 1) / (1.0 - pow(q, player_num));
		cout << fixed << setprecision(4) << ans << endl;
	}

	//system("PAUSE");
	return 0;
}