遞歸：在一個函數裏調用這個函數本身

修給遞歸的最大深度

import sys
print(sys.setrecursionlimit(100000))

　遞歸實現三級菜單

 1 menu = {
 2     ‘北京‘: {
 3         ‘海澱‘: {
 4             ‘五道口‘: {
 5                 ‘soho‘: {},
 6                 ‘網易‘: {},
 7                 ‘google‘: {}
 8             },
 9             ‘中關村‘: {
10                 ‘
 
愛奇藝‘: {},
11                 ‘汽車之家‘: {},
12                 ‘youku‘: {},
13             },
14             ‘上地‘: {
15                 ‘百度‘: {},
16             },
17         },
18         ‘昌平‘: {
19             ‘沙河‘: {
20                 ‘老男孩‘: {},
21                 ‘北航‘: {},
22             },
23             ‘
 
天通苑‘: {},
24             ‘回龍觀‘: {},
25         },
26         ‘朝陽‘: {},
27         ‘東城‘: {},
28     },
29     ‘上海‘: {
30         ‘閔行‘: {
31             "人民廣場": {
32                 ‘炸雞店‘: {}
33             }
34         },
35         ‘閘北‘: {
36             ‘火車戰‘: {
37                 ‘攜程‘: {}
38             }
 
39         },
40         ‘浦東‘: {},
41     },
42     ‘山東‘: {},
43 }
44 
45 def three(dic):
46     for key in dic:
47         print(key)
48     k = input(‘>>>>>>>‘)
49     if k in dic:
50         three(dic[k])
51 three(dic)

二分查找算法：

l = [2,3,5,10,15,16,18,22,26]
def find(l,aim,start,end):
    mid = (end+start)//2
    if l[mid] > aim:    #中間值大於目標值，左邊尋找
        end = mid   #頭部不變，
        return find(l,aim,start,end)
    elif l[mid] < aim:
        start= mid
        return find(l,aim,start,end)
    else:
        return mid
print(find(l,15,start=0,end=len(l)-1))

遞歸與二分算法