Add Euclidean Algorithm in PowerShell

.editorconfig

@@ -157,3 +157,9 @@ indent_size = 0
 trim_trailing_whitespace = false
 insert_final_newline = false
 end_of_line = lf
+
+
+# PowerShell
+[*.ps1]
+indent_style = space
+indent_size = 4

book.json

@@ -192,6 +192,10 @@
  {
  "lang": "ss",
  "name": "Scheme"
+ },
+ {
+ "lang": "ps1",
+ "name": "PowerShell"
  }
  ]
  }

contents/euclidean_algorithm/code/powershell/euclidean_algorithm.ps1

@@ -0,0 +1,30 @@
+function Sub-Euclid($a, $b) {
+ $a = [Math]::Abs($a)
+ $b = [Math]::Abs($b)
+
+ while ($a -ne $b) {
+ if ($a -gt $b) {
+ $a = $a - $b
+ } else {
+ $b = $b - $a
+ }
+ }
+
+ return $a
+}
+
+function Mod-Euclid($a, $b) {
+ $a = [Math]::Abs($a)
+ $b = [Math]::Abs($b)
+
+ while ($b -ne 0) {
+ $tmp = $b
+ $b = $a % $b
+ $a = $tmp
+ }
+
+ return $a
+}
+
+Write-Host "Subtraction-based euclidean algorithm result: $(Mod-Euclid $(64 * 67) $(64 * 81))"
+Write-Host "Modulus-based euclidean algorithm result: $(Sub-Euclid $(128 * 12) $(128 * 77))"

contents/euclidean_algorithm/euclidean_algorithm.md

@@ -75,6 +75,10 @@ The algorithm is a simple way to find the *greatest common divisor* (GCD) of two
 <p>
  <img class="center" src="code/scratch/euclid_sub.svg" width="200" />
 </p>
+# leave one line empty:
+
+{% sample lang="ps1" %}
+[import:1-14, lang="powershell"](code/powershell/euclidean_algorithm.ps1)
 
 {% endmethod %}
 
@@ -157,6 +161,10 @@ Modern implementations, though, often use the modulus operator (%) like so
 <p>
  <img class="center" src="code/scratch/euclid_mod.svg" width="200" />
 </p>
+# leave one line empty:
+
+{% sample lang="ps1" %}
+[import:16-27, lang="powershell"](code/powershell/euclidean_algorithm.ps1)
 
 {% endmethod %}
 
@@ -264,6 +272,10 @@ The code snippets were taken from this [Scratch project](https://scratch.mit.edu
 <p>
  <img class="center" src="code/scratch/main.svg" width="200" />
 </p>
+# leave one line empty:
+
+{% sample lang="ps1" %}
+[import, lang="powershell"](code/powershell/euclidean_algorithm.ps1)
 
 {% endmethod %}