PowerShell/docs/measure-SelectionSort.md
2024-11-20 11:52:20 +01:00

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The *measure-SelectionSort.ps1* Script
===========================
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
/home/markus/Repos/PowerShell/scripts/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
🧭 0.335 sec to sort 1000 integers by SelectionSort
```
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
🧭 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 as of 11/20/2024 11:51:57)*