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Problem Description

WhereIsHeroFrom:             Zty, what are you doing ?

Zty:                                     I want to calculate N!...... WhereIsHeroFrom:             So easy! How big N is ? Zty:                                    1 <=N <=1000000000000000000000000000000000000000000000… WhereIsHeroFrom:             Oh! You must be crazy! Are you Fa Shao? Zty:                                     No. I haven's finished my saying. I just said I want to calculate N! mod 2009 Hint : 0! = 1, N! = N*(N-1)!

 

 

Input

Each line will contain one integer N(0 <= N<=10^9). Process to end of file.

 

 

Output

For each case, output N! mod 2009

 

 

Sample Input

4

5

 

 

Sample Output

24

120

 

 

Author

WhereIsHeroFrom

代码及注释如下：

/*2009及之后的mod2009都等于0;前面的测了一下发现41mod2009就等于0了...综上40之后的mod2009=0.40之前的需要算一波*/#include 
   
    #include 
    
     #include 
     
      #include 
      
       using namespace std;int a[50];int n;void Init(){   a[0]=1;   a[1]=1;   for (int i=2;i<=40;i++)   {       a[i]=a[i-1]*i%2009;   }}int main(){    Init();    while (scanf("%d",&n)!=EOF)    {         if(n<=40)            printf("%d\n",a[n]);         else            printf("0\n");    }    return 0;}
      
     
    
   

 

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