Climbing Stairs

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?
问题描述：一个有n层阶梯的楼梯，每次可以爬一层或者两层，问总共有多少种走法。
采用动态规划的思想：
climbStairs(n)=climbStairs(n-1)+climbStairs(n-2);
climbStairs(1)=1;
climbStairs(2)=2;

class Solution {public:    int climbStairs(int n) {        /*    //递归超时        if(n==1)            return 1;        else if(n==2)            return 2;        else            return climbStairs(n-1)+climbStairs(n-2);            */        if(n==1)               return 1;        else if(n==2)            return 2;        int rst[n];  //[思想与Unique Path类似](http://blog.csdn.net/weixin_37701236/article/details/61917731)        rst[0]=1;        rst[1]=2;        for(int i=2;i<n;i++)            rst[i]=rst[i-1]+rst[i-2];        return rst[n-1];    }};