PowerShell/Docs/measure-SelectionSort.md

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2023-09-01 17:53:03 +02:00
*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
----------
```powershell
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
-------
```powershell
PS> ./measure-SelectionSort.ps1
🧭 Sorting 1000 integers by SelectionSort took 0.3351773 sec
```
Notes
-----
Author: Markus Fleschutz | License: CC0
Related Links
-------------
https://github.com/fleschutz/PowerShell
Script Content
--------------
```powershell
<#
.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
🧭 Sorting 1000 integers by SelectionSort took 0.3351773 sec
.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
"🧭 Sorting $numIntegers integers by SelectionSort took $elapsed sec"
exit 0 # success
```
*(generated by convert-ps2md.ps1 using the comment-based help of measure-SelectionSort.ps1 as of 09/01/2023 17:51:53)*