70_climbing_stairs.py

class Solution:
    def climbStairs(self, n: int) -> int:
        # F(n) = F(n-1) + F(n-2) (if n > 2)
        if n == 1:
            return 1
        elif n == 2:
            return 2
        else:
            nums = [0, 1, 2]
            for i in range(3, n+1):
                nums.append(nums[i-1] + nums[i-2])
            return nums[n]

'''
    This is my personal record of solving Leetcode Problems. 
    If you have any questions, please discuss them in [Issues](https://github.com/mengxinayan/leetcode/issues).
    Copyright (C) 2020-2022  mengxinayan

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
'''