斐波那契数列非递归算法(fibonacci)

package c4;

public class FibTest {
	public static void main(String []args ){
		long begin = System.currentTimeMillis() ;
		System.out.println(fib(10)) ;
		long end = System.currentTimeMillis() ;
		System.out.println(end-begin) ;
	}
	public static long fib(int n){
		if (n<=2){
			return 1;
		}else {
			long s1 =1;
			long s2=1;
			for(int i=2;i<n-1;i++){
				s2 = s1+s2;
				s1 = s2-s1 ;
				System.out.println("s1:"+s1+" s2:"+s2); 
			}
			return s1+s2;
		}
		
	}
}

s1:1 s2:2
s1:2 s2:3
s1:3 s2:5
s1:5 s2:8
s1:8 s2:13
s1:13 s2:21
s1:21 s2:34
55
1