PowerShell/Docs/measure-SelectionSort.md

measure-SelectionSort.ps1

This PowerShell script measures the speed of the SelectionSort algorithm. SelectionSort is an in-place comparison sorting algorithm. It has an O(n2) time complexity, which makes it inefficient on large lists, and generally performs worse than the similar insertion sort. Selection sort is noted for its simplicity and has performance advantages over more complicated algorithms in certain situations, particularly where auxiliary memory is limited.

Parameters

PS> ./measure-SelectionSort.ps1 [[-numIntegers] <Int32>] [<CommonParameters>]

-numIntegers <Int32>
    Specifies the number of integers to sort
    
    Required?                    false
    Position?                    1
    Default value                1000
    Accept pipeline input?       false
    Accept wildcard characters?  false

[<CommonParameters>]
    This script supports the common parameters: Verbose, Debug, ErrorAction, ErrorVariable, WarningAction, 
    WarningVariable, OutBuffer, PipelineVariable, and OutVariable.

Example

PS> ./measure-SelectionSort.ps1
🧭 0.335 sec to sort 1000 integers by SelectionSort

Notes

Author: Markus Fleschutz | License: CC0

Related Links

https://github.com/fleschutz/PowerShell

Script Content

<#
.SYNOPSIS
        Measures the speed of SelectionSort
.DESCRIPTION
        This PowerShell script measures the speed of the SelectionSort algorithm.
        SelectionSort is an in-place comparison sorting algorithm. It has an O(n2) time complexity,
	which makes it inefficient on large lists, and generally performs worse than the similar
	insertion sort. Selection sort is noted for its simplicity and has performance advantages
	over more complicated algorithms in certain situations, particularly where auxiliary memory
	is limited. 
.PARAMETER numIntegers
        Specifies the number of integers to sort
.EXAMPLE
        PS> ./measure-SelectionSort.ps1
	🧭 0.335 sec to sort 1000 integers by SelectionSort
.LINK
        https://github.com/fleschutz/PowerShell
.NOTES
        Author: Markus Fleschutz | License: CC0
#>

param([int]$numIntegers = 1000)

class SelectionSort {
    static Sort($targetList) {
        $n = $targetList.count

        for ($i = 0; $i -lt $n; $i++) {
            for ($j = $i + 1; $j -lt $n; $j++) {
                if ($targetList[$j] -lt $targetList[$i]) {
                    $tmp = $targetList[$i]
                    $targetList[$i] = $targetList[$j]
                    $targetList[$j] = $tmp
                }
            }
        }
    }
}

$list = (1..$numIntegers | foreach{Get-Random -minimum 1 -maximum $numIntegers})
$stopWatch = [system.diagnostics.stopwatch]::startNew()
[SelectionSort]::Sort($list)
[float]$elapsed = $stopWatch.Elapsed.TotalSeconds
$elapsed3 = "{0:N3}" -f $elapsed # formatted to 3 decimal places
"🧭 $elapsed3 sec to sort $numIntegers integers by SelectionSort"
exit 0 # success

(generated by convert-ps2md.ps1 using the comment-based help of measure-SelectionSort.ps1 as of 10/19/2023 08:11:40)