leetcode#70. Climbing Stairs

题目

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.
很无聊的题，其实就是个斐波那契数列，虽然我没搞懂是怎么回事，但是试了前几个数试出来的，哈哈

代码

class Solution(object):    def climbStairs(self, n):        """        :type n: int        :rtype: int        """        pre = 1        after = 2        i = 1        while i < n:            temp = pre            pre = after            after += temp            i += 1        return pre

总结

很无聊的水题，不过在小嘎嘎那里学到了简洁的写法，可以避免temp的应用

r, a, b = 0, 0, 1while r < n:    a, b = b, a + b    r = r + 1return r