一只青蛙一次可以跳1阶或者2阶，n阶，有多少种到达终点的方式。

一个面试遇到的题

# -*-encoding:utf-8-*-
import sys


def jump(journey, walked=None, counter=None):

    if walked is None:
        walked = []
    if counter is None:
        counter = []
    for step in [1, 2]:
        walking = walked + [step]
        if sum(walking) >= journey:
            print(walking)
            counter.append(1)
            continue
        jump(journey, walking, counter)
    return len(counter)


def main(journey):
    print(jump(journey))


if __name__ == "__main__":
    main(5)

 

[1, 1, 1, 1, 1]
[1, 1, 1, 1, 2]
[1, 1, 1, 2]
[1, 1, 2, 1]
[1, 1, 2, 2]
[1, 2, 1, 1]
[1, 2, 1, 2]
[1, 2, 2]
[2, 1, 1, 1]
[2, 1, 1, 2]
[2, 1, 2]
[2, 2, 1]
[2, 2, 2]
13

 

这个题主要就是考算法-递归