Maze generation: Difference between revisions

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@@ Line 2,617: / Line 2,617: @@
 Here I generate a maze as a graph. Vertices of the graph are cells and edges of the graph are removed walls. This version is mush faster and is convenient to solve.
 <lang mathematica>MazeGraph[m_, n_] :=
-  Block[{$RecursionLimit = Infinity, grid = GridGraph[{m, n}],
+ Block[{$RecursionLimit = Infinity, grid = GridGraph[{m, n}],
+   unvisitedQ}, unvisitedQ[_] := True;
-    visited = {}},
-   Graph[Range[m n], Reap[{AppendTo[visited, #];
+  Graph[Range[m n], Reap[{unvisitedQ[#] = False;
-         Do[
+        Do[
-          If[FreeQ[visited, neighbor],
+         If[unvisitedQ[neighbor],
-           Sow[# <-> neighbor]; #0@neighbor], {neighbor,
+          Sow[# <-> neighbor]; #0@neighbor], {neighbor,
-           RandomSample@AdjacencyList[grid, #]}]} &@
+          RandomSample@AdjacencyList[grid, #]}]} &@
-       RandomChoice@VertexList@grid][[2, 1]],
+      RandomChoice@VertexList@grid][[2, 1]],
-    GraphLayout -> {"GridEmbedding", "Dimension" -> {m, n}}]];
+   GraphLayout -> {"GridEmbedding", "Dimension" -> {m, n}}]];
 maze = MazeGraph[13, 21]</lang>
 {{Out}}