climbing_stairs.py

#https://leetcode.com/problems/climbing-stairs/description/
class Solution(object):
    def climbStairs(self, n):
        """
        :type n: int
        :rtype: int
        """
        def climb(n):

            if n==1: #only one step option is availble
                 return 1
            if n ==2: # two options are possible : to take two 1-stpes or to only take one 2-steps
                 return 2
            return climb(n-1) + climb(n-2)
        return climb(n)