hdu 3853 LOOPS 概率DP

简单的概率DP入门题

代码如下：

 #include<iostream>
 #include<stdio.h>
 #include<algorithm>
 #include<iomanip>
 #include<cmath>
 #include<cstring>
 #include<vector>
 #define ll __int64
 #define pi acos(-1.0)
 #define MAX 1003
 using namespace std;
 struct point
 {
     double c,b,r;
 }p[MAX][MAX];
 double dp[MAX][MAX];
 int main(){
     int n,m,i,j;
     while(scanf("%d%d",&n,&m)!=EOF){
         for(i=;i<=n;i++)
             for(j=;j<=m;j++)
                 scanf("%lf%lf%lf",&p[i][j].c,&p[i][j].r,&p[i][j].b);
         dp[n][m]=0.0;
         for(i=n;i>=;i--)
         for(j=m;j>=;j--){
             if(i==n&&j==m) continue;
             if(fabs(-p[i][j].c)<1e-) continue;
             dp[i][j]=(p[i][j].r*dp[i][j+]+p[i][j].b*dp[i+][j]+)/(-p[i][j].c);
         }
         printf("%.3lf\n",dp[][]);
     }
     return ;
 }