HDU 3853 概率dp

#include <cstdio>
#include <cmath>
const int maxn = 1E3 + 10;
const double eps = 1e-8;
double dp[maxn][maxn], p1[maxn][maxn], p2[maxn][maxn], p3[maxn][maxn];
int R, C;
int main(int argc, char const *argv[])
{
while (~scanf("%d%d", &R, &C) && R + C)
{
for (int i = 1; i <= R; i++)
for (int j = 1; j <= C; j++)
scanf("%lf%lf%lf", &p1[i][j], &p2[i][j], &p3[i][j]);
dp[R][C] = 0;
for (int i = R; i >= 1; i--)
for (int j = C; j >= 1; j--)
{
if (i == R && j == C) continue;
if (fabs(1 - p1[i][j]) < eps) continue;
dp[i][j] = p2[i][j] / (1 - p1[i][j]) * dp[i][j + 1] + p3[i][j] / (1 - p1[i][j]) * dp[i + 1][j] + 2 / (1 - p1[i][j]);
}
printf("%.3lf\n", dp[1][1]);
}
return 0;
}