1 #include <iostream> 2 #include <cstring> 3 #include <cstdio> 4  5 using namespace std; 6  7 int m, t, n; 8 double dp[1005][40][40]; 9 double p[1005][40];10 double p1, p2;11 12 int main()13 {14     while (scanf("%d%d%d", &m, &t, &n) && m) { //这里的&&写成了&，wa了1个小时15         memset(dp, 0, sizeof(dp));16         for (int i = 1; i <= t; i++) {17             for (int j = 1; j <= m; j++) 18                 scanf("%lf", &p[i][j]);19         }20 21         for (int i = 1; i <= t; i++) {22             23             dp[i][0][0] = 1.0;24             for (int j = 1; j <= m; j++) {25                 dp[i][j][0] = dp[i][j - 1][0] * (1 - p[i][j]);26             27                 for (int l = 1; l <= j; l++) {28                     dp[i][j][l] = dp[i][j - 1][l] * (1 - p[i][j]) 29                                 + dp[i][j - 1][l - 1] * p[i][j];    30                 }31             }32         }33 34         double s1 = 1;35         double s2 = 1;36         37         for (int i = 1; i <= t; i++) {38             p1 = 0;39             for (int j = 1; j < n; j++) 40                 p1 += dp[i][m][j];41             s1 *= p1;42         }43 44         45         for (int i = 1; i <= t; i++) {46             p2 = 1 - dp[i][m][0];47             s2 *= p2;48         }49         printf("%.3lf\n", s2 - s1);50     }51     return 0;52 }