https://leetcode.com/problems/climbing-stairs/
You are climbing a stair case. It takes n steps to reach to the top.
Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?
Note: Given n will be a positive integer.
Example 1:
Input: 2 Output: 2 Explanation: There are two ways to climb to the top. 1. 1 step + 1 step 2. 2 steps
Example 2:
Input: 3 Output: 3 Explanation: There are three ways to climb to the top. 1. 1 step + 1 step + 1 step 2. 1 step + 2 steps 3. 2 steps + 1 step
代码：
class Solution {
public:
int climbStairs(int n) {
int a[10010];
a[0] = a[1] = 1;
for(int i = 2; i < 10010; i ++)
a[i] = a[i - 1] + a[i - 2];
return a[n];
}
};