RosettaCodeData/Task/Maze-generation/Delphi/maze-generation.delphi

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program MazeGen_Rosetta;
{$APPTYPE CONSOLE}
uses System.SysUtils, System.Types, System.Generics.Collections, System.IOUtils;
type
TMCell = record
Visited : Boolean;
PassTop : Boolean;
PassLeft : Boolean;
end;
TMaze = array of array of TMCell;
TRoute = TStack<TPoint>;
const
mwidth = 24;
mheight = 14;
procedure ClearVisited(var AMaze: TMaze);
var
x, y: Integer;
begin
for y := 0 to mheight - 1 do
for x := 0 to mwidth - 1 do
AMaze[x, y].Visited := False;
end;
procedure PrepareMaze(var AMaze: TMaze);
var
Route : TRoute;
Position : TPoint;
d : Integer;
Pool : array of TPoint; // Pool of directions to pick randomly from
begin
SetLength(AMaze, mwidth, mheight);
ClearVisited(AMaze);
Position := Point(Random(mwidth), Random(mheight));
Route := TStack<TPoint>.Create;
try
with Position do
while True do
begin
repeat
SetLength(Pool, 0);
if (y > 0) and not AMaze[x, y-1].Visited then Pool := Pool + [Point(0, -1)];
if (x < mwidth-1) and not AMaze[x+1, y].Visited then Pool := Pool + [Point(1, 0)];
if (y < mheight-1) and not AMaze[x, y+1].Visited then Pool := Pool + [Point(0, 1)];
if (x > 0) and not AMaze[x-1, y].Visited then Pool := Pool + [Point(-1, 0)];
if Length(Pool) = 0 then // no direction to draw from
begin
if Route.Count = 0 then Exit; // and we are back at start so this is the end
Position := Route.Pop;
end;
until Length(Pool) > 0;
d := Random(Length(Pool));
Offset(Pool[d]);
AMaze[x, y].Visited := True;
if Pool[d].y = -1 then AMaze[x, y+1].PassTop := True; // comes from down to up ( ^ )
if Pool[d].x = 1 then AMaze[x, y].PassLeft := True; // comes from left to right ( --> )
if Pool[d].y = 1 then AMaze[x, y].PassTop := True; // comes from left to right ( v )
if Pool[d].x = -1 then AMaze[x+1, y].PassLeft := True; // comes from right to left ( <-- )
Route.Push(Position);
end;
finally
Route.Free;
end;
end;
function MazeToString(const AMaze: TMaze; const S, E: TPoint): String; overload;
var
x, y: Integer;
v : Char;
begin
Result := '';
for y := 0 to mheight - 1 do
begin
for x := 0 to mwidth - 1 do
if AMaze[x, y].PassTop then Result := Result + '+'#32#32#32 else Result := Result + '+---';
Result := Result + '+' + sLineBreak;
for x := 0 to mwidth - 1 do
begin
if S = Point(x, y) then v := 'S' else
if E = Point(x, y) then v := 'E' else
v := #32'*'[Ord(AMaze[x, y].Visited) + 1];
Result := Result + '|'#32[Ord(AMaze[x, y].PassLeft) + 1] + #32 + v + #32;
end;
Result := Result + '|' + sLineBreak;
end;
for x := 0 to mwidth - 1 do Result := Result + '+---';
Result := Result + '+' + sLineBreak;
end;
procedure Main;
var
Maze: TMaze;
begin
Randomize;
PrepareMaze(Maze);
ClearVisited(Maze); // show no route
Write(MazeToString(Maze, Point(-1, -1), Point(-1, -1)));
ReadLn;
end;
begin
Main;
end.