归并排序 

 1 import random
 2 
 3 
 4 def merge(mer_l, mer_r):
 5     new_list = []
 6     i = 0
 7     j = 0
 8     len_l = len(mer_l)
 9     len_r = len(mer_r)
10     while len_l > i and len_r > j:
11         if mer_l[i] < mer_r[j]:
12             new_list.append(mer_l[i])
13             i += 1
14         else:
15             new_list.append(mer_r[j])
16             j += 1
17     while i < len_l:
18         new_list.append(mer_l[i])
19         i += 1
20     while j < len_r:
21         new_list.append(mer_r[j])
22         j += 1
23     return new_list
24 
25 
26 def _merge_sort(li, low, mid, high):
27     if high > low:
28         _merge_sort(li, low, (low+mid)//2, mid)
29         _merge_sort(li, mid+1, (mid+1+high)//2, high)
30         li[low:high+1] = merge(li[low:mid+1], li[mid+1:high+1])
31 
32 
33 def merge_sort(li):
34     high = len(li) - 1
35     low = 0
36     mid = (high + low)//2
37     _merge_sort(li, low, mid, high)
38 
39 
40 if __name__ == '__main__':
41     li3 = list(range(100))
42     random.shuffle(li3)
43     print(li3)
44     merge_sort(li3)
45     print(li3)

 

posted @ 2021-12-05 10:03  Avery_rainys  阅读(25)  评论(0)    收藏  举报