LeetCode #70 - Climbing Stairs

题目描述：

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?

某一级要么是从它下一级的爬上来的，要么是从它的下两级爬上来的。

class Solution {
public:
    int climbStairs(int n) 
	{
        int v[n+1];
        v[0]=1;
        v[1]=1;
        for(int i=2;i<=n;i++)
        {
        	v[i]=v[i-1]+v[i-2];
        }
        return v[n];
    }
};