70. Climbing Stairs （dp）

https://leetcode.com/problems/climbing-stairs/description/

题目： 略

思路：简单dp

class Solution {public:    int climbStairs(int n) {        int dp[1000005];        dp[0]=dp[1]=1;        for(int x=2;x<=n;x++)  dp[x]=dp[x-1]+dp[x-2];        return dp[n];    }};