K_程式人

https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=997

#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;

}