Python daily delicious (30)-Fast sorting of Python data structures and algorithms

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• 1. Quick sorting
• 4. Results

The principle of quick sorting is to extract the first number and divide the entire array into two waves. One dial is greater than this number, and the other wave is smaller than this number, then recursively process the first and second digits in the same way. All of them are "quick sorting", and the efficiency is certainly better than other general sorting.AlgorithmHigh. Let's verify the performance difference between the so-called "Quick Sort" and "bubble sort.

1. Quick sorting Def Quicksort ( Data , Low = 0 , High = None ):
If High = None :
High = Len ( Data ) - 1
If Low < High :
S , I , J = Data [ Low ], Low , High
While I < J :
While I < J And Data [ J ] > = S :
J = J - 1
If I < J :
Data [ I ] = Data [ J ]
I = I + 1
While I < J And Data [ I ] <= S :
I = I + 1
If I < J :
Data [ J ] = Data [ I ]
J = J - 1
Data [ I ] = S
Quicksort ( Data , Low , I - 1 )
Quicksort ( Data , I + 1 , High ) 2. Bubble Sorting
Def Bubblesort ( Data ):
For I In Range ( Len ( Data ) - 1 , 0 , - 1 ):
For J In Range ( 0 , I ):
If Data [ J ] > Data [ J + 1 ]:
Data [ J ], Data [ J + 1 ] = Data [ J + 1 ], Data [ J ]

 

3. Performance Comparison

It seems that the Bubble Sorting only requires five rows, Which is concise enough, but what is the performance? To compare:

Import Random
Import Datetime
Import Copy

Def Sort_perfmon ( Sortfunc , Data ):
Sort_data = Copy . Deepcopy ( Data )
T1 = Datetime . Datetime . Now ()
Sortfunc ( Sort_data )
T2 = Datetime . Datetime . Now ()
Print Sortfunc . _ Name __ , T2 - T1
# Print sort_data

Data = [ Random . Randint ( 0 , 65536 ) For I In Range ( 2000 )]
# Print data
Sort_perfmon ( Quicksort , Data )
Sort_perfmon ( Bubblesort , Data )

 

4. Results

By sorting 2000 random numbers, the following results show that the advantage of fast sorting is very large.

Quicksort 0:00:00. 062000
Bubblesort 0:00:03. 563000

 

5.CodeDownload

Http://files.cnblogs.com/coderzh/Code/sorttest.rar

 

 

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