hdu3853LOOPS概率dp

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <cstring>
using namespace std;
const int N=1005;
const double eps=1e-9;
int r,c;
double p1[N][N],p2[N][N],p3[N][N],dp[N][N];
int main()
{
    while(scanf("%d%d",&r,&c)!=EOF){
        memset(dp,0,sizeof(dp));
        for(int i=0;i<r;i++)
            for(int j=0;j<c;j++)
                scanf("%lf%lf%lf",&p1[i][j],&p2[i][j],&p3[i][j]);
        int j;
        for(int i=r-1;i>=0;i--)//(i==r-1&&j==c-1)把這個放到這裏====bug
        for(j=c-1;j>=0;j--){
            if((i==r-1&&j==c-1)||fabs(p1[i][j]-1.0)<eps) continue;
            dp[i][j]=(dp[i][j+1]*p2[i][j]+dp[i+1][j]*p3[i][j]+2)/(1-p1[i][j]);
        }
        printf("%.3lf\n",dp[0][0]);
    }
    return 0;
}