Climbing Stairs
You are climbing a staircase. It takes n steps to reach the top.
Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?
Example 1:
Input: n = 2
Output: 2
Explanation: There are two ways to climb to the top.
1. 1 step + 1 step
2. 2 steps
Example 2:
Input: n = 3
Output: 3
Explanation: There are three ways to climb to the top.
1. 1 step + 1 step + 1 step
2. 1 step + 2 steps
3. 2 steps + 1 step
Solution:
class Solution:
# 通过列举可知,1阶有1种方法,2阶有2种方法,3阶有3种方法,
# 4阶有5种方法,其符合斐波那契数列,n阶=n-1阶+n-2阶,
# 于是可用列表s[n]记入n阶有的方法数,并通过s.append()进行记入。
def climbStairs(self, n: int) -> int:
s=[1,2]
if n<=2: # 若为一步就数组第一个值,若为两步就第二个值
return s[n-1]
while len(s)<n:
s.append(s[-1]+s[-2])
return s[-1]
人生便是艺术。