> import java.math.*;
> import java.util.*;
> 
> public class Main
> {
> 	static final int Max = 51;
> 	static long pow2[], C[][];
> 	static BigInteger num[];
> 	
> 	public static void init()
> 	{
> 		pow2 = new long[Max];
> 		C = new long[Max][Max];
> 		pow2[0] = 1;
> 		int i, j;
> 		for(i = 1;i < Max;++ i) pow2[i] = pow2[i-1] * 2;
> 		for(i = 0;i < Max;++ i) C[i][0] = C[i][i] = 1;
> 		for(i = 1;i < Max;i ++)
> 			for(j = 1;j < i;j ++)
> 				C[i][j] = C[i-1][j-1] + C[i-1][j];
> 		
> 		num = new BigInteger[Max];
> 		num[1] = BigInteger.valueOf(1);
> 		for(i = 2;i < Max;i ++)
> 		{
> 			num[i] = BigInteger.valueOf(0);
> 			for(j = 1;j < i;j ++)
> 			{
> 				BigInteger tmp = BigInteger.valueOf(1);
> 				tmp = tmp.multiply(num[j]);
> 				tmp = tmp.multiply(num[i-j]);
> 				tmp = tmp.multiply(BigInteger.valueOf(pow2[j] - 1));
> 				tmp = tmp.multiply(BigInteger.valueOf(C[i-2][j-1]));
> 				num[i] = num[i].add(tmp);
> 			}
> 		}
> 	}
> 	public static void main(String[] args)
> 	{
> 		Scanner sc = new Scanner(System.in);
> 		init();
> 		while(sc.hasNextInt())
> 		{
> 			int n = sc.nextInt();
> 			System.out.println(num[n]);
> 		}
> 	}
> }

• 回的正快，帮我看看 (0) flyingfish 2006-10-06 18:18:20
  • 输入不对吧…… (0) frkstyc 2006-10-06 18:19:38
    • Re:输入不对吧……　那要怎样写，我写的３个版本的输入了 (0) flyingfish 2006-10-06 18:21:12
      • 拜托……输入用0结束好不好…… (0) frkstyc 2006-10-06 18:22:27
        • 晕，没看清楚 (0) flyingfish 2006-10-06 18:23:17