java大数 斐波那契数列

java大数做斐波那契数列：
 思路:1.
      2.可以用数组存着

import java.math.BigInteger;
import java.util.Scanner;
public class Main{

    public static void main(String[] args) {
        Scanner cin=new Scanner(System.in);
        while(cin.hasNext()){//remermber
            BigInteger num1=cin.nextBigInteger();
            BigInteger num2=cin.nextBigInteger();
            BigInteger num3=cin.nextBigInteger();
            BigInteger num4 = null;
            for(int i=4;i<=100;++i){
                num4=num1.add(num2).add(num3);
                if(i%3==1){
                    num1=num4;
                }else if(i%3==2){
                    num2=num4;
                }else{
                    num3=num4;
                }
            }
            System.out.println(num4);
        }
    }

}