合并排序_python

 1 #!/usr/bin/python
 2 # --coding:utf-8 --
 3 
 4 def sort_merge(left,right):
 5     i,j=0,0
 6     result=[]
 7     while i<len(left) and j<len(right):
 8         if left[i]<right[j]:
 9             result.append(left[i])
10             i+=1
11         else:
12             result.append(right[j])
13             j+=1
14     result+=left[i:]
15     result+=right[j:]
16     return result
17 
18 
19 def sortdata(input):
20     if len(input)==1:
21         return input
22     index=len(input)//2
23     left=sortdata(input[:index])
24     right=sortdata(input[index:])
25     return sort_merge(left,right)
26 
27 print(sortdata([3,5,9,10,13,35,56]))
28 
29 
30 
31 # left                       right
32 # 3,5,9                     10,3,35,56
33 # left  right            left         right
34 # 3      5,9             10 ,3         35,56
35 #        left right      left  right    left  right
36 #         5     9          10    3       35     56