动态规划篇了
class Solution(object):
def climbStairs(self, n):
"""
:type n: int
:rtype: int
"""
if n == 0:
return 0
if n == 1:
return 1
if n == 2:
return 2
p1 = 1
p2 = 2
p = 3
for i in range(3,n+1):
p = p1 + p2
p1, p2 = p2, p
return p
