1.循环

 1 public class T009 {

 2     public static void main(String[] args){

 3         System.out.println(fibonacci(3));

 4     }

 5     public static long fibonacci(int n){

 6         int[] result = {0,1};

 7         if(n<2)

 8             return result[n];

 9         long fibminOne=1;

10         long fibminTwo=0;

11         long fibN = 0;

12         for(int i =2;i<=n;i++){

13             fibN = fibminOne+fibminTwo;

14             fibminTwo=fibminOne;

15             fibminOne=fibN;

16         }

17         return fibN;

18     }

19 }

2.递归

java实现——009Fibonacci数列