--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wilsons.rb	Sun Sep 15 11:46:47 2019 +0200
@@ -0,0 +1,41 @@
+#---
+# Excerpted from "Mazes for Programmers",
+# published by The Pragmatic Bookshelf.
+# Copyrights apply to this code. It may not be used to create training material, 
+# courses, books, articles, and the like. Contact us if you are in doubt.
+# We make no guarantees that this code is fit for any purpose. 
+# Visit http://www.pragmaticprogrammer.com/titles/jbmaze for more book information.
+#---
+class Wilsons
+
+  def on(grid)
+    unvisited = [] 
+    grid.each_cell { |cell| unvisited << cell }
+
+    first = unvisited.sample 
+    unvisited.delete(first) 
+
+    while unvisited.any? 
+      cell = unvisited.sample 
+      path = [cell]
+
+      while unvisited.include?(cell) 
+        cell = cell.neighbors.sample 
+        position = path.index(cell) 
+        if position
+          path = path[0..position] 
+        else
+          path << cell 
+        end
+      end 
+
+      0.upto(path.length-2) do |index| 
+        path[index].link(path[index + 1]) 
+        unvisited.delete(path[index]) 
+      end 
+    end
+
+    grid
+  end
+
+end