mirror of
https://github.com/fleschutz/PowerShell.git
synced 2024-12-15 11:10:54 +01:00
55 lines
1.8 KiB
PowerShell
Executable File
55 lines
1.8 KiB
PowerShell
Executable File
<#
|
|
.SYNOPSIS
|
|
Measures the speed of QuickSort
|
|
.DESCRIPTION
|
|
This PowerShell script measures the speed of the QuickSort algorithm.
|
|
QuickSort is an in-place sorting algorithm. Developed by British computer scientist
|
|
Tony Hoare in 1959 and published in 1961, it is still a commonly used algorithm for
|
|
sorting. When implemented well, it can be somewhat faster than merge sort and about
|
|
two or three times faster than heapsort.
|
|
.PARAMETER numIntegers
|
|
Specifies the number of integers to sort
|
|
.EXAMPLE
|
|
PS> ./measure-QuickSort.ps1
|
|
🧭 0.085 sec to sort 1000 integers by QuickSort
|
|
.LINK
|
|
https://github.com/fleschutz/PowerShell
|
|
.NOTES
|
|
Author: Markus Fleschutz | License: CC0
|
|
#>
|
|
|
|
param([int]$numIntegers = 1000)
|
|
|
|
class QuickSort {
|
|
static Sort($targetList, $left, $right) {
|
|
$i=$left
|
|
$j=$right
|
|
$pivot = $targetList[($left+$right)/2]
|
|
|
|
while($i -le $j) {
|
|
while($targetList[$i] -lt $pivot -and $i -lt $right) {$i++}
|
|
while($targetList[$j] -gt $pivot -and $j -gt $left) {$j--}
|
|
|
|
if($i -le $j) {
|
|
$tmp = $targetList[$i]
|
|
$targetList[$i]=$targetList[$j]
|
|
$targetList[$j]=$tmp
|
|
|
|
$i++
|
|
$j--
|
|
}
|
|
}
|
|
|
|
if($left -lt $j) {[QuickSort]::Sort($targetList, $left, $j)}
|
|
if($i -lt $right) {[QuickSort]::Sort($targetList, $i, $right)}
|
|
}
|
|
}
|
|
|
|
$list = (1..$numIntegers | foreach{Get-Random -minimum 1 -maximum $numIntegers})
|
|
$stopWatch = [system.diagnostics.stopwatch]::startNew()
|
|
[QuickSort]::Sort($list, 0, $list.Count-1)
|
|
[float]$elapsed = $stopWatch.Elapsed.TotalSeconds
|
|
$elapsed3 = "{0:N3}" -f $elapsed # formatted to 3 decimal places
|
|
"🧭 $elapsed3 sec to sort $numIntegers integers by QuickSort"
|
|
exit 0 # success
|