mirror of
https://github.com/fleschutz/PowerShell.git
synced 2025-08-09 21:07:40 +02:00
Renamed folder Scripts to scripts
This commit is contained in:
59
scripts/measure-CountingSort.ps1
Executable file
59
scripts/measure-CountingSort.ps1
Executable file
@ -0,0 +1,59 @@
|
||||
<#
|
||||
.SYNOPSIS
|
||||
Measures the speed of CountingSort
|
||||
.DESCRIPTION
|
||||
This PowerShell script measures the speed of the CountingSort algorithm.
|
||||
CountingSort is an algorithm for sorting a collection of objects according to keys
|
||||
that are small positive integers; that is, it is an integer sorting algorithm. It
|
||||
operates by counting the number of objects that possess distinct key values, and
|
||||
applying prefix sum on those counts to determine the positions of each key value in
|
||||
the output sequence. Its running time is linear in the number of items and the difference
|
||||
between the maximum key value and the minimum key value, so it is only suitable for direct
|
||||
use in situations where the variation in keys is not significantly greater than the number
|
||||
of items. It is often used as a subroutine in radix sort, another sorting algorithm, which
|
||||
can handle larger keys more efficiently.
|
||||
.PARAMETER numIntegers
|
||||
Specifies the number of integers to sort
|
||||
.EXAMPLE
|
||||
PS> ./measure-CountingSort.ps1
|
||||
🧭 0.045 sec to sort 1000 integers by CountingSort
|
||||
.LINK
|
||||
https://github.com/fleschutz/PowerShell
|
||||
.NOTES
|
||||
Author: Markus Fleschutz | License: CC0
|
||||
#>
|
||||
|
||||
param([int]$numIntegers = 1000)
|
||||
|
||||
class CountingSort {
|
||||
static Sort($targetList) {
|
||||
$min = 0
|
||||
$max = 0
|
||||
|
||||
for ($counter = 0; $counter -lt $targetList.Count; $counter++) {
|
||||
if ($targetList[$counter] -lt $min) { $min = $targetList[$counter] }
|
||||
if ($targetList[$counter] -gt $max) { $max = $targetList[$counter] }
|
||||
}
|
||||
|
||||
$arrayBucket = New-Object int[] ($max - $min + 1)
|
||||
|
||||
for ($counter = 0; $counter -lt $targetList.Count; $counter++) {
|
||||
$arrayBucket[$targetList[$counter]]++;
|
||||
}
|
||||
|
||||
$lastPosition = 0
|
||||
for ($counter = 0; $counter -lt $arrayBucket.Count ; $counter++) {
|
||||
for ($innerCounter = 0; $innerCounter -lt $arrayBucket[$counter]; $innerCounter++) {
|
||||
$targetList[$lastPosition++] = $counter
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
$list = (1..$numIntegers | foreach{Get-Random -minimum 1 -maximum $numIntegers})
|
||||
$stopWatch = [system.diagnostics.stopwatch]::startNew()
|
||||
[CountingSort]::Sort($list)
|
||||
[float]$elapsed = $stopWatch.Elapsed.TotalSeconds
|
||||
$elapsed3 = "{0:N3}" -f $elapsed # formatted to 3 decimal places
|
||||
"🧭 $elapsed3 sec to sort $numIntegers integers by CountingSort"
|
||||
exit 0 # success
|
Reference in New Issue
Block a user