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105 lines
3.1 KiB
Markdown
105 lines
3.1 KiB
Markdown
Script: *measure-QuickSort.ps1*
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========================
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This PowerShell script measures the speed of the QuickSort algorithm.
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QuickSort is an in-place sorting algorithm. Developed by British computer scientist
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Tony Hoare in 1959 and published in 1961, it is still a commonly used algorithm for
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sorting. When implemented well, it can be somewhat faster than merge sort and about
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two or three times faster than heapsort.
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Parameters
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----------
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```powershell
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PS> ./measure-QuickSort.ps1 [[-numIntegers] <Int32>] [<CommonParameters>]
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-numIntegers <Int32>
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Specifies the number of integers to sort
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Required? false
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Position? 1
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Default value 1000
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Accept pipeline input? false
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Accept wildcard characters? false
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[<CommonParameters>]
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This script supports the common parameters: Verbose, Debug, ErrorAction, ErrorVariable, WarningAction,
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WarningVariable, OutBuffer, PipelineVariable, and OutVariable.
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```
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Example
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-------
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```powershell
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PS> ./measure-QuickSort.ps1
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🧭 0.085 sec to sort 1000 integers by QuickSort
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```
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Notes
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-----
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Author: Markus Fleschutz | License: CC0
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Related Links
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-------------
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https://github.com/fleschutz/PowerShell
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Script Content
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--------------
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```powershell
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<#
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.SYNOPSIS
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Measures the speed of QuickSort
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.DESCRIPTION
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This PowerShell script measures the speed of the QuickSort algorithm.
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QuickSort is an in-place sorting algorithm. Developed by British computer scientist
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Tony Hoare in 1959 and published in 1961, it is still a commonly used algorithm for
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sorting. When implemented well, it can be somewhat faster than merge sort and about
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two or three times faster than heapsort.
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.PARAMETER numIntegers
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Specifies the number of integers to sort
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.EXAMPLE
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PS> ./measure-QuickSort.ps1
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🧭 0.085 sec to sort 1000 integers by QuickSort
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.LINK
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https://github.com/fleschutz/PowerShell
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.NOTES
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Author: Markus Fleschutz | License: CC0
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#>
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param([int]$numIntegers = 1000)
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class QuickSort {
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static Sort($targetList, $left, $right) {
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$i=$left
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$j=$right
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$pivot = $targetList[($left+$right)/2]
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while($i -le $j) {
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while($targetList[$i] -lt $pivot -and $i -lt $right) {$i++}
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while($targetList[$j] -gt $pivot -and $j -gt $left) {$j--}
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if($i -le $j) {
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$tmp = $targetList[$i]
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$targetList[$i]=$targetList[$j]
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$targetList[$j]=$tmp
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$i++
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$j--
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}
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}
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if($left -lt $j) {[QuickSort]::Sort($targetList, $left, $j)}
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if($i -lt $right) {[QuickSort]::Sort($targetList, $i, $right)}
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}
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}
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$list = (1..$numIntegers | foreach{Get-Random -minimum 1 -maximum $numIntegers})
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$stopWatch = [system.diagnostics.stopwatch]::startNew()
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[QuickSort]::Sort($list, 0, $list.Count-1)
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[float]$elapsed = $stopWatch.Elapsed.TotalSeconds
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$elapsed3 = "{0:N3}" -f $elapsed # formatted to 3 decimal places
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"🧭 $elapsed3 sec to sort $numIntegers integers by QuickSort"
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exit 0 # success
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```
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*(generated by convert-ps2md.ps1 using the comment-based help of measure-QuickSort.ps1 as of 08/15/2024 09:50:51)*
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