Climbing Stairs

public class Solution {
public int climbStairs(int n) {
int f1 = 2;
int f2 = 1;
if(n<=0) return 0;
if(n==1) return f2;
if(n==2) return f1;
int fn=0;
for(int i=2;i<n;i++){
fn=f1+f2;
f2=f1;
f1=fn;
}
return fn;
}
}

Climbing Stairs

原文：http://www.cnblogs.com/krunning/p/3538797.html