Uses CRT;

Const
  N=20;
  M=20;
  DIVISOR = 1.7;

  EMPTY_CELL = 0;
  WRONG_WAY  = 1;
  WAY        = 2;

  Colors:Array[EMPTY_CELL..WAY] Of Byte = (Green,Yellow,Red);

Var
  Maze:Array[0..N-1,0..M-1] Of Byte;

Procedure GenerateMaze;
Var
  i,j:Integer;
  x,y:Integer;
Begin
  For i:=0 To N-1 Do
    For j:=0 To M-1 Do
      Maze[i,j]:=EMPTY_CELL;
  x:=0;
  y:=0;
  While (x < N-1) Or (y < M-1) Do
  Begin
    Maze[x,y]:=WAY;
    If (Random>0.5) Then
      If x < N-1 Then
        Inc(x)
      Else
        Inc(y)
    Else
      If y < M-1 Then
        Inc(y)
      Else
        Inc(x)
  End;
  Maze[x,y]:=WAY;
  For i:=1 To Round(N*M/DIVISOR) Do
  Begin
    x:=Random(N);
    y:=Random(M);
    If (Maze[x,y]=EMPTY_CELL) Then
      Maze[x,y]:=WRONG_WAY
  End
End;

Procedure DrawMaze;
Var
  i,j:Integer;
Begin
  ClrScr;
  For i:=0 To N-1 Do
  Begin
    For j:=0 To M-1 Do
    Begin
      TextBackground(Colors[Maze[i,j]]);
      Write(' ')
    End;
    WriteLn
  End
End;

Begin
  Randomize;
  GenerateMaze;
  DrawMaze;
  ReadKey
End.