HDU 1023 Traning Problem （2） 大数卡特兰数

用java做就很好做了 套公式就可以了

import java.io.*;
import java.util.*;
import java.math.BigInteger;  

public class Main
{
    public static void main(String args[])
    {
        BigInteger[] a = new BigInteger[101];
        a[0] = BigInteger.ZERO;
        a[1] = BigInteger.valueOf(1);
        for(int i = 2; i <= 100; ++i)
            a[i] = a[i - 1].multiply(BigInteger.valueOf(4 * i - 2)).divide(BigInteger.valueOf(i+1));
            Scanner in = new Scanner(System.in);
            int n;
            while(in.hasNext())
            {
                n = in.nextInt();
                System.out.println(a[n]);
            }
    }
}