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?

DP最简单的题目

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