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?
class Solution(object): def climbStairs(self, n): """ :type n: int :rtype: int """ w = [0]*n if n == 0: return 0 if n == 1: return 1 if n == 2: return 2 w[0] = 1 w[1] = 2 for i in range(2,n): w[i] = w[i-1]+w[i-2] return w[n-1]