hdu2583

#include <iostream>#include <cstdio>#include <string>#include <cstring>#include <algorithm>#include <cmath>int main(){int dp[101][101];memset(dp,0,sizeof(dp));dp[1][0]=1;dp[1][1]=0;int i,j;for (i=2;i<=100;i++){dp[i][0]=1;for (j=1;j<=i-1;j++)dp[i][j]=(dp[i-1][j]*(j+1)%2009+dp[i-1][j-1]*(i-j)%2009)%2009;}int n,m;while (scanf("%d",&n)!=EOF){scanf("%d",&m);printf("%d\n",dp[n][m]);}}