poj 2084 Game of Connections

题目链接：http://poj.org/problem?id=2084

题目思路：递推，枚举与点1连接的点即可。

import java.math.BigInteger;
import java.util.Scanner;

public class Main
{
	public static void main(String[] args)
	{
		int n,i,j;
		BigInteger[]dp=new BigInteger[102];
		Scanner sc=new Scanner(System.in);
		dp[0]=BigInteger.ONE;
		for(i=1;i<=101;i++)
		{
			dp[i]=BigInteger.ZERO;
			for(j=0;j<i;j++)
			{
				dp[i]=dp[i].add(dp[j].multiply(dp[i-1-j]));
			}
		}
		while(sc.hasNext())
		{
			n=sc.nextInt();
			if(n==-1)
				break;
			System.out.println(dp[n]);
		}
	}
}