Double layer cave generator

This dungeon generator is mainly based on Cellular Automata Method, so I suggest to read that article first. With my generator modification, you will generate absolutely random caves, and there will not be any unreachable disconnected space.

Algorithm

In words there are only 3 (or 4, if you want less open space) steps:

• Generate one map by Cellular Automata method.
• Generate another map with that method.
• Fuse both maps: Check both map arrays. If the first map's square is "wall", and the second map's is "wall", then invert and make it a "stepable" square. Otherwise, do not invert and keep it a "wall". If the first map's square is "stepable" and the second map's square is too, then invert and make it a "wall", else keep it a "stepable square".
• (Optional step) Generate random walls: I.e. if there are 3 or less "walls" in a 3 square radius around another square, make that square also a "wall". Or something like that.

Also, here is dirty(we can join some loops) code in Pascal language:

  program Map_Gen;
   uses crt;
   var x, y: array [1..116,1..50,1..5] of char;
   xx: array[1..116,1..50] of integer;
   i, j, q, qq, ii, jj, ax, ay, k:integer;
begin
   Randomize;
   
   for i:=1 to 50 do
       for j:=1 to 116 do begin
           If (i=1) or (i=50) or (j=1) or (j=116) then xx[j,i]:=-1
           else xx[j,i]:=0;
       end;

   for i:=1 to 50 do
       for j:=1 to 116 do begin
           If (i=1) or (i=50) or (j=1) or (j=116) then begin
               x[j,i,1]:='#';
               x[j,i,5]:='#';
               y[j,i,1]:='#';
           end
           else begin
               q:=random(100);
               if q<45 then x[j,i,1]:='#'
               else x[j,i,1]:='.';
               qq:=random(100);
               if qq<45 then y[j,i,1]:='#'
               else y[j,i,1]:='.';
           end;
       end;
   
   for k:=2 to 5 do begin
       TextColor(k);
       for i:=2 to 49 do begin
           for j:=2 to 115 do begin
               ax:=0;
               ay:=0;
               for ii:=(i-1) to (i+1) do begin
                   for jj:=(j-1) to (j+1) do begin
                       If (x[jj,ii,k-1]='#') then ax:=ax+1;
                       If (y[jj,ii,k-1]='#') then ay:=ay+1;
                   end;
               end;
               If ((x[j,i,k-1]='#') and (ax>3)) or (ax>4) then begin
                   x[j,i,k]:='#';
               end
               else begin
                   x[j,i,k]:='.';
               end;
               If ((y[j,i,k-1]='#') and (ay>3)) or (ay>4) then begin
                   y[j,i,k]:='#';
               end
               else begin
                   y[j,i,k-1]:='.';
               end;
           end;
       end;
   end;
   
   for i:=2 to 49 do begin
       for j:=2 to 115 do begin
           Case x[j,i,5] of
           '#':    if x[j,i,5]=y[j,i,5] then begin
                       x[j,i,5]:='.';
                       xx[j,i]:=0;
                   end
                   else begin
                       x[j,i,5]:='#';
                       xx[j,i]:=-1;
                   end;
           '.':    if x[j,i,5]=y[j,i,5] then begin
                       x[j,i,5]:='#';
                       xx[j,i]:=-1;
                   end
                   else begin
                       x[j,i,5]:='.';
                       xx[j,i]:=0;
                   end;
           end;
       end;
   end;
   
   for i:=22 to 28 do
       for j:=55 to 61 do begin
           x[j,i,5]:='.';
           xx[j,i]:=0;
       end;
       
   xx[58,25]:=1;

   for k:=1 to 50 do
       for i:=2 to 49 do
           for j:=2 to 115 do begin
               if xx[j,i]=k then begin
                   for ii:=(i-1) to (i+1) do begin
                       for jj:=(j-1) to (j+1) do begin
                           if (xx[jj,ii]=0) then xx[jj,ii]:=k+1;
                       end;
                   end;
               end;
           end;

   for i:=2 to 49 do
       for j:=2 to 115 do begin
           if (xx[j,i]=0) and (x[j,i,5]='.') then begin
           x[j,i,5]:='#';
           end;
       end;

   for i:=1 to 50 do
       for j:=1 to 116 do begin
           GoToXY(j,i);
           Write(x[j,i,5]);
       end;
   Readln;
end.