代码改变世界

leetcode - Climbing Stairs

2013-03-05 21:32  张汉生  阅读(187)  评论(0)  编辑  收藏  举报

题目描述：点击此处

 1 class Solution {
 2 public:
 3     int climbStairs(int n) {
 4         // Start typing your C/C++ solution below
 5         // DO NOT write int main() function
 6         if (n<=0)
 7             return 0;
 8         if (n==1)
 9             return 1;
10         int current, lastTwo = 1,lastOne=1;
11         int i;
12         for (i=2; i<=n; i++){
13             current = lastTwo + lastOne;
14             if (i==n)
15                 return current;
16              lastTwo = lastOne;
17              lastOne = current;
18         }
19         return 0;
20     }
21 };