leetcode_question_70 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?

 

int climbStairs(int n) {

        // Start typing your C/C++ solution below

        // DO NOT write int main() function

        if(n < 2)

            return 1;

        int* dp = new int[n];

        dp[0] = 1;

        dp[1] = 1;

        for(int i = 2; i < n; ++i)

            dp[i] = dp[i-2] + dp[i-1];

        int res = dp[n-2] + dp[n-1];

        delete[] dp;

        return res;

    }