Climbing Stairs LeetCode solution in Python

1
class Solution(object):
2
    def climbStairs(self, n):
3
        """
4
        :type n: int
5
        :rtype: int
6
        """
7
        memo = {}
8
        memo[1] = 1
9
        memo[2] = 2
10

11
        def climb(n):
12
            if (
13
                n in memo
14
            ):  # if the recurssion already done before first take a look-up in the look-up table
15
                return memo[n]
16
            else:  # Store the recurssion function in the look-up table and reuturn the stored look-up table function
17
                memo[n] = climb(n - 1) + climb(n - 2)
18
                return memo[n]
19

20
        return climb(n)