CDOJ 631 敢说敢做 记忆化搜索and动规

//跟沈爷学的 传送门http://www.cnblogs.com/Xiper/p/4639636.html

 #include<cstdio>
 #include<iostream>
 #include<cmath>
 #include<algorithm>
 #include<cstring>
 #include<cstdlib>
 #include<queue>
 #include<vector>
 #include<map>
 #include<stack>
 #include<string>

 using namespace std;

 const long long MOD=;

 long long n,k;
 long long C[][];
 long long dp[][];

 long long dfs(long long x,long long y){
     if (dp[x][y]!=-) return dp[x][y];
     if (x== && y==) return ;
     if (x!= && y==) return ;
     dp[x][y]=;
     for (long long i=;i<=x-y+;i++){
             dp[x][y]=(dp[x][y]+dfs(x-i,y-)*C[x][i]%MOD)%MOD;
     }
     return dp[x][y];
 }

 int main(){
     memset(dp,-,sizeof(dp));
     memset(C,,sizeof(C));
     for (long long i=;i<=;i++) C[i][]=;
     for (long long i=;i<=;i++){
             for (long long j=;j<=;j++){
                     C[i][j]=(C[i-][j]+C[i-][j-])%MOD;
             }
     }
     while (scanf("%lld%lld",&n,&k)==){
             printf("%lld\n",dfs(n,k));
     }
     return ;
 }
 /*
 1 1
 2 2
 */