[Leetcode]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?

简单动规。

class Solution {
public:
    int climbStairs(int n) {
        if(n<3)
            return n;
        int* path = new int[n+1];
        path[1]=1;path[2]=2;
        for(int i=3;i!=n+1;i++)
            path[i]=path[i-1]+path[i-2];
        return path[n];
    }
};