hdu 3853 LOOPS 概率DP

简单的概率DP入门题

代码如下:

 

 1 #include<iostream>
 2 #include<stdio.h>
 3 #include<algorithm>
 4 #include<iomanip>
 5 #include<cmath>
 6 #include<cstring>
 7 #include<vector>
 8 #define ll __int64
 9 #define pi acos(-1.0)
10 #define MAX 1003
11 using namespace std;
12 struct point
13 {
14     double c,b,r;
15 }p[MAX][MAX];
16 double dp[MAX][MAX];
17 int main(){
18     int n,m,i,j;
19     while(scanf("%d%d",&n,&m)!=EOF){
20         for(i=1;i<=n;i++)
21             for(j=1;j<=m;j++)
22                 scanf("%lf%lf%lf",&p[i][j].c,&p[i][j].r,&p[i][j].b);
23         dp[n][m]=0.0;
24         for(i=n;i>=1;i--)
25         for(j=m;j>=1;j--){
26             if(i==n&&j==m) continue;
27             if(fabs(1-p[i][j].c)<1e-5) continue;
28             dp[i][j]=(p[i][j].r*dp[i][j+1]+p[i][j].b*dp[i+1][j]+2)/(1-p[i][j].c);
29         }
30         printf("%.3lf\n",dp[1][1]);
31     }
32     return 0;
33 }
View Code

 

 

 

posted @ 2013-08-09 08:51  _随心所欲_  阅读(196)  评论(0编辑  收藏  举报