Add Jarvis March in PowerShell

contents/jarvis_march/code/powershell/JarvisMarch.ps1

@@ -0,0 +1,52 @@
+function New-Point($x, $y) {
+    return New-Object -TypeName PSObject -Property @{X = [int]$x; Y = [int]$y}
+}
+
+function CounterClockWise($p1, $p2, $p3) {
+    return (($p3.Y - $p1.Y) * ($p2.X - $p1.X)) -ge (($p2.Y - $p1.Y) * ($p3.X - $p1.X))
+}
+
+function jarvis-march($gift) {
+    [System.Collections.ArrayList]$gift = $gift | Get-Unique -AsString
+    $pointOnHull = $gift | Sort-Object -Property X | Select-Object -First 1
+    [System.Collections.ArrayList]$hull = @($pointOnHull)
+
+    while ($true) {
+        $endpoint = $gift[0]
+
+        $gift | Select-Object -Skip 1 | ForEach-Object {
+            if (($endpoint -eq $pointOnHull) -or (-not (CounterClockWise $_ $hull[-1] $endpoint))) {
+                $endpoint = $_
+            }
+        }
+
+        $pointOnHull = $endpoint
+
+        if ($hull[0] -eq $endpoint) {
+            return $hull
+        } else {
+            $hull.Add($pointOnHull) | Out-Null
+        }
+    }
+}
+
+$testGift = @(
+        (New-Point -5 2)
+        (New-Point 5 7)
+        (New-Point -6 -12)
+        (New-Point -14 -14)
+        (New-Point 9 9)
+        (New-Point -1 -1)
+        (New-Point -10 11)
+        (New-Point -6 15)
+        (New-Point -6 -8)
+        (New-Point 15 -9)
+        (New-Point 7 -7)
+        (New-Point -2 -9)
+        (New-Point 6 -5)
+        (New-Point 0 14)
+        (New-Point 2 8)
+)
+
+$hull = Jarvis-March $testGift
+Write-Host "The points in the hull are: $($hull | % {"($($_.X), $($_.Y)) "})"

contents/jarvis_march/jarvis_march.md

@@ -50,6 +50,8 @@ Since this algorithm, there have been many other algorithms that have advanced t
 [import, lang:"v"](code/v/jarvis.v)
 {% sample lang="rust" %}
 [import, lang:"rust"](code/rust/jarvis_march.rs)
+{% sample lang="ps1" %}
+[import, lang:"powershell"](code/powershell/JarvisMarch.ps1)
 {% endmethod %}
 
 <script>