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?

 

 

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