递归函数与三级菜单
menu = {'北京': {'海淀': {'五道口': {'soho': {},'网易': {},'google': {}},'中关村': {'爱奇艺': {},'汽车之家': {},'youku': {},},'上地': {'百度': {},},},'昌平': {'沙河': {'老男孩': {},'北航': {},},'天通苑': {},'回龙观': {},},'朝阳': {},'东城': {},},'上海': {'闵行': {"人民广场": {'炸鸡店': {}}},'闸北': {'火车战': {'携程': {}}},'浦东': {},},'山东': {}, }
def caidan(dic):if dic:for k in dic:print(k)city = input('>>>')if city in dic:return caidan(dic[city])else:return '没找到啊'else:return "传入的字典是空的" print(caidan(menu))
def threeLM(dic):while True:for k in dic: print(k)key = input('input>>').strip()if key == 'b' or key == 'q': return keyelif key in dic.keys() and dic[key]:ret = threeLM(dic[key])if ret == 'q': return 'q'threeLM(menu)
二分查找算法
二分查只能用在排序过得序列中
l = [2,3,5,10,15,16,18,22,26,30,32,35,41,42,43,55,56,66,67,69,72,76,82,83,88]
def search(num,l,start=None,end=None):start = start if start else 0end = end if end is None else len(l) - 1mid = (end - start)//2 + startif start > end:return Noneelif l[mid] > num :return search(num,l,start,mid-1)elif l[mid] < num:return search(num,l,mid+1,end)elif l[mid] == num:return mid
