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?
Note: Given n will be a positive integer.
Example 1:
Input: 2 Output: 2 Explanation: There are two ways to climb to the top. 1. 1 step + 1 step 2. 2 steps
Example 2:
Input: 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
Recursion with memory:
M(n)=M(n-1)+M(n-2)
class Solution(object):
def climbStairs(self, n):
"""
:type n: int
:rtype: int
"""
a=[0]*n
def findM(n):
if n==1:
a[0]=1
return 1
elif n==2:
a[1]=2
return 2
else:
if a[n-1-1]==0:
a[n-1-1]=findM(n-1)
if a[n-2-1]==0:
a[n-2-1]=findM(n-2)
a[n-1]=a[n-1-1]+a[n-2-1]
return a[n-1]
findM(n)
return a[n-1]
[LeetCode&Python] Problem 70. Climbing Stairs
原文：https://www.cnblogs.com/chiyeung/p/10164355.html