TODAY'S HEADLINES  |   ARTICLE ARCHIVE  |   FORUMS  |   TIP BANK
 Specialized Dev Zones Research Center eBook Library .NET Java C++ Web Dev Architecture Database Security Open Source Enterprise Mobile Special Reports 10-Minute Solutions DevXtra Blogs Slideshow

Language: Visual Basic
Expertise: Intermediate
Feb 3, 1999

### WEBINAR:On-Demand

Building the Right Environment to Support AI, Machine Learning and Deep Learning

# Improve on the Bubble Sort

A bubble sort's execution time is a multiple of the square of the number of elements. Because of this, the bubble sort is said to be an n-squared algorithm. You can easily make improvements to a bubble sort to speed it up.

One way is to reverse the direction of passes reading the array, instead of always reading the array in the same direction. This makes out-of-place elements travel quickly to their correct position. This version of a bubble sort is called the shaker sort, because it imparts a shaking motion to the array:

``````
Public Sub Shaker(Item() As Variant)
Dim Exchange As Boolean
Dim Temp As Variant
Dim x As Integer

Do
Exchange = False
For x = (UBound(Item)) To (LBound(Item) + 1) Step -1
If Item(x - 1) > Item(x) Then
Temp = Item(x - 1)
Item(x - 1) = Item(x)
Item(x) = Temp
Exchange = True
End If
Next x

For x = (LBound(Item) + 1) To (UBound(Item))
If Item(x - 1) > Item(x) Then
Temp = Item(x - 1)
Item(x - 1) = Item(x)
Item(x) = Temp
Exchange = True
End If
Next x
Loop While Exchange
End Sub
``````
Although the shaker sort improves the bubble sort, it still executes as an n-squared algorithm. However, because most programmers can code a bubble sort with their eyes closed, this is a nice way to shave 25 to 33 percent off the required execution time without having to dig out the algorithm books. Still, you don't want to use either a bubble or shaker sort for extremely large data sets.
Tan Shing

 Submit a Tip Browse "XML" Tips Browse All Tips
Comment and Contribute

(Maximum characters: 1200). You have 1200 characters left.

Thanks for your registration, follow us on our social networks to keep up-to-date