Fibonacci 取余，直接做超时

超时：
import java.lang.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.io.*;
class Main
{
    public static void main(String []args)
    {
        Scanner cin=new Scanner(System.in);
        BigInteger f[]=new BigInteger[1000];
        BigInteger g=BigInteger.valueOf(10),e;
        BigInteger l=BigInteger.valueOf(10000);
        int i,n,m;
        while(cin.hasNext())
        {
                n=cin.nextInt();
                f[0]=BigInteger.valueOf(0);
                f[1]=BigInteger.valueOf(1);
                f[2]=BigInteger.valueOf(1);
                if(n>1)
                {
                    for(i=2;i<=n;i++)
                    {
                        f[2]=f[1].add(f[0]);
                        f[0]=f[1];
                        f[1]=f[2];
                    }
                    e=f[2];
                    while(e.compareTo(l)<0)
                    {
                        e=e.divide(g);
                    }
                    System.out.println(f[2]);
                }
                else if(n==1)System.out.println(1);
                else System.out.println(0);
        }
    }
}

 

import java.math.*;
import java.lang.*;
import java.text.*;
import java.util.*;
import java.io.*;  
class Main
{
    public static void main(String[] args)
    {
        Scanner cin=new Scanner(System.in);
        int arr[]={0,1,1,2,3,5,8,13,21,34,55,89,144,233,377,610,987,1597,2584,4181,6765},n;   
        while(cin.hasNext())
        {
            n=cin.nextInt();
            if(n<=20)
            {
                System.out.println(arr[n]);
                continue;
            }
            else
            {
                double m=Math.log10(1.0/Math.sqrt(5))+n*Math.log10((1+Math.sqrt(5))/2);
                double p=m-(int)m;
                p=Math.pow(10,p);
                while(p<1000)
                {
                    p*=10;
                }
                System.out.println((int)p);
            }
        }
    }
}