hdu 4405 Aeroplane chess (期望dp入门)

http://acm.hdu.edu.cn/showproblem.php?pid=4405

 1 #include<cstdio>
 2 #include<cstring>
 3 #include<algorithm>
 4 #include<iostream>
 5 using namespace std;
 6 
 7 const int mx=100000+10;
 8 int v[mx];
 9 double dp[mx];
10 
11 int main()
12 {
13     int n,m,x,y,i,j;
14     while (cin>>n>>m)
15     {
16         memset(v,0,sizeof(v));
17         memset(dp,0,sizeof(dp));
18         if (!n&&!m) return 0;
19         while (m--)
20         {
21             cin>>x>>y;
22             v[x]=y;
23         }
24         for (i=n-1;i>=0;i--)
25         {
26             if (v[i]) {dp[i]=dp[v[i]];continue;}
27             for (j=i+1;j<=i+6;j++)
28                 dp[i]+=(dp[j]+1)/6.0;
29         }
30         printf("%.4lf\n",dp[0]);
31     }
32 }

posted on 2016-03-10 21:10 pb2016 阅读(148) 评论(0) 编辑收藏举报