HDU 1023 Train Problem II （卡特蘭數問題）

Train Problem II

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 2830    Accepted Submission(s): 1562

Problem Description

As we all know the Train Problem I, the boss of the Ignatius Train Station want to know if all the trains come in strict-increasing order, how many orders that all the trains can get out of the railway.

 

 

Input

The input contains several test cases. Each test cases consists of a number N(1<=N<=100). The input is terminated by the end of file.

 

 

Output

For each test case, you should output how many ways that all the trains can get out of the railway.

 

 

Sample Input

1 2 3 10

 

 

Sample Output

1 2 5 16796

Hint

The result will be very large, so you may not process it by 32-bit integers.

 

 

Author

Ignatius.L

 

 

 

簡單的卡特蘭數問題。

卡特蘭數介紹：

http://www.cnblogs.com/kuangbin/archive/2012/03/21/2410516.html

 

這個已經可以做為模版了~~~

//ｈ( n ) = ( ( 4*n-2 )/( n+1 )*h( n-1 ) );


#include<stdio.h>

//*******************************
//打表卡特蘭數
//第 n個 卡特蘭數存在a[n]中，a[n][0]表示長度；
//注意數是倒着存的，個位是 a[n][1] 輸出時注意倒過來。 
//*********************************
int a[105][100];
void ktl()
{
    int i,j,yu,len;
    a[2][0]=1;
    a[2][1]=2;
    a[1][0]=1;
    a[1][1]=1;
    len=1;
    for(i=3;i<101;i++)
    {
        yu=0;
        for(j=1;j<=len;j++)
        {
            int t=(a[i-1][j])*(4*i-2)+yu;
            yu=t/10;
            a[i][j]=t%10;
        }    
        while(yu)
        {
            a[i][++len]=yu%10;
            yu/=10;
        }
        for(j=len;j>=1;j--)
        {
            int t=a[i][j]+yu*10;
            a[i][j]=t/(i+1);
            yu = t%(i+1);
        }        
        while(!a[i][len])
        {
            len--;
        }    
        a[i][0]=len;
    }    
    
}    
int main()
{
    ktl();
    int n;
    while(scanf("%d",&n)!=EOF)
    {
        for(int i=a[n][0];i>0;i--)
        {
            printf("%d",a[n][i]);
        }    
        puts("");
    }    
    return 0;
}