hdu2643

Rank

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 399    Accepted Submission(s): 193

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

AC代码：
#include <iostream>
#include <cstdio>
#include <algorithm>
#define LL __int64
#define MOD 20090126
using namespace std;
LL str[101][101];
LL con[101];
void initial()
{
        con[0]=1;
        for(LL i=1;i<=100;i++)
        con[i]=(con[i-1]*i)%MOD;
        for(LL i=0;i<=100;i++)
        {
                for(LL j=0;j<=i;j++)
                {
                        if(i==j)
                                str[i][j]=1;
                        else if(j==0&&i>=1)
                                str[i][j]=0;
                        else
                        {
                                str[i][j]=((j*str[i-1][j])%MOD+str[i-1][j-1])%MOD;
                        }
                }
        }
}
int main()
{
        initial();
        LL n,T;
        scanf("%I64d",&T);
        while(T--)
        {
                scanf("%I64d",&n);
                LL ans=0;
                for(LL i=1;i<=n;i++)
                ans=(ans+(str[n][i]*con[i])%MOD)%MOD;
                printf("%I64d\n",ans);
        }
        return 0;
}