Leetcode#70 Climbing Stairs

 1 int climbStairs(int n) {
 2         if (n <= 0)
 3             return 0;
 4             
 5         int count = 1;
 6         int tmp = 1;
 7         
 8         for (int i = 2; i <= n; i++) {
 9             int t = count;
10             count += tmp;
11             tmp = t;
12         }
13         
14         return count;
15 }