Description
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
class Solution(object):
def climbStairs(self, n):
"""
:type n: int
:rtype: int
"""
way=[1,1]
for i in range(n-1):
tmp=way[1]
way[1]+=way[0]
way[0]=tmp
return way[1]