Java-斐波那契数

 1 public class Test {
 2     
 3     //The Fibonacci Sequence is the series of numbers:0, 1, 1, 2, 3, 5, 8, 13, 21, 34, ...
 4     public long fab(int index){
 5         
 6         if(index==1 || index==2){
 7             return index-1;
 8         }
 9         
10         long f1 = 0L;
11         long f2 = 1L;
12         long f3 = 0;
13         
14         for(int i=2 ;i < index ;i++ ){
15             f3 = f2+f1;
16             f1 = f2;
17             f2 = f3;
18         }
19         return f3;
20     }
21 
22     @org.junit.Test
23     public void test(){
24         System.out.println(fab(8));
25     }
26 }