【第二类斯特林数】HDU_2643_Rank

Rank

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 604    Accepted Submission(s): 307

Problem Description

Recently in Teddy's hometown there is a competition named "Cow Year Blow Cow".N competitors had took part in this competition.The competition was so intense that the rank was changing and changing.
Now the question is:
How many different ways that n competitors can rank in a competition, allowing for the possibility of ties. 
as the answer will be very large,you can just output the answer MOD 20090126.
Here are the ways when N = 2:
P1 < P2
P2 < P1
P1 = P2 

 

Input

The first line will contain a T,then T cases followed.
each case only contain one integer N (N <= 100),indicating the number of people.

 

Output

One integer pey line represent the answer MOD 20090126.

 

Sample Input

  

   2
2
3
  

 

Sample Output

  

   3
13
  

 

Author

teddy

 

Source

百万秦关终属楚

 

Recommend

teddy

#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
const int maxn=110;
const int mod=20090126;
LL dp[maxn][maxn],f[maxn];
void Init(int n){
    dp[0][0]=1;f[0]=1;
    for(int i=1;i<=n;i++){
        f[i]=i*f[i-1]%mod;
        for(int j=1;j<=i;j++)
            dp[i][j]=((j%mod*dp[i-1][j]%mod)%mod+dp[i-1][j-1]%mod)%mod;
    }
}
int main()
{
    int t,n;
    Init(100);
    scanf("%d",&t);
    while(t--){
        LL ans=0;
        scanf("%d",&n);
        for(int i=1;i<=n;i++)
            ans=(ans+dp[n][i]*f[i])%mod;
        printf("%I64d\n",ans);
    }
    return 0;
}