poj 2151
实在没有发现这个题和二分查找或hash有啥关系....
1 #include <iostream> 2 #include <string> 3 #include <vector> 4 #include <cstdlib> 5 #include <cmath> 6 #include <map> 7 #include <algorithm> 8 #include <list> 9 #include <ctime> 10 #include <set> 11 #include <string.h> 12 #include <queue> 13 #include <cstdio> 14 using namespace std; 15 #define CLR(arr, what) memset(arr, what, sizeof(arr)) 16 double pro[1002][32]; 17 double dp[1002][32]; 18 int main() { 19 int M, T, N; 20 21 scanf("%d%d%d", &M, &T, &N); 22 while (M || T || N) { 23 CLR(pro, 0); 24 CLR(dp, 0); 25 for (int i = 0; i < T; i++) { 26 for (int j = 0; j < M; j++) { 27 scanf("%lf", &pro[i][j]); 28 } 29 } 30 for (int i = 0; i < T; i++) { 31 dp[i][0] = 1 - pro[i][0]; 32 dp[i][1] = pro[i][0]; 33 for (int j = 1; j < M; j++) { 34 for (int k = j + 1; k >= 0; k--) { 35 switch (k) { 36 case 0: 37 dp[i][k] = dp[i][k] * (1 - pro[i][j]); 38 break; 39 default: 40 dp[i][k] = dp[i][k] * (1 - pro[i][j]) 41 + dp[i][k - 1] * (pro[i][j]); 42 break; 43 } 44 } 45 } 46 } 47 double p1, p2; 48 p1 = 1; 49 p2 = 1; 50 for (int i = 0; i < T; i++) { 51 double t1, t2; 52 t1 = 0; 53 t2 = 0; 54 for (int j = 1; j < N; j++) { 55 t1 = t1 + dp[i][j]; 56 } 57 t2=1-dp[i][0]; 58 p1 = p1 * t1; 59 p2 = p2 * t2; 60 } 61 printf("%.3lf\n", p2 - p1); 62 scanf("%d%d%d", &M, &T, &N); 63 } 64 return 0; 65 }
