poj2506

高精度递推，用java

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

public class Main {
    static public void main (String[] args)throws FileNotFoundException
    {
        Scanner cin = new Scanner(new BufferedInputStream(System.in));
        //Scanner cin = new Scanner(new FileInputStream("t.txt"));
        BigInteger[] f = new BigInteger[260];
        f[0] = BigInteger.valueOf(1);
        f[1] = BigInteger.valueOf(1);
        for (int i = 2; i <= 250 ; i++)
            f[i] = f[i - 1].add(f[i - 2].multiply(BigInteger.valueOf(2)));
        while (cin.hasNext())
        {
            int a = cin.nextInt();
            System.out.println(f[a]);
        }
    }
}