Lang:Java
Edit12345678910111213141516171819202122import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scan = new Scanner(System.in);int N = scan.nextInt();int M = scan.nextInt();double[] Pi = new double[N+1];for (int i = 1; i < Pi.length; i++) {Pi[i] = scan.nextDouble();}double[][] dp = new double[N+1][N+1];dp[0][0] = 1;for (int i = 1; i < dp.length; i++) {dp[i][0] = dp[i-1][0] * (1-Pi[i]);for (int j = 1; j <= i; j++) {dp[i][j] = dp[i-1][j-1] * Pi[i] + dp[i-1][j] * (1-Pi[i]);}}System.out.println(dp[N][M]);}}