Uses crt;
Const snake='*'; eat='';
      MaxLen=200;
      InitLen=1;
Type posit = record
          x : Integer;
          y : Integer;
            end;
Var A : Array[1..MaxLen] of posit;
    col : Integer;
    Crazy : Boolean;
    N, fx, fy : Integer;
    score : Integer;
    time : Integer;

Procedure NewFood;
begin
  Score:=Score+10;
  If Time > 1 then Time:=Time-1;
  fx:=Random(78)+2;
  fy:=Random(48)+2;
  GotoXY(fx, fy); TextColor(14); Write(eat);
  If N<MaxLen then N:=N+1;
end;

Procedure debug(x,y : Integer);
begin
  GotoXY(1,1); TextColor(15);
  Write('snake : ', x:4, y:4,'       food : ', fx:4, fy:4,'      score : ',score:4,'   speed :', (101-time) : 4, '%');
end;

Procedure draw(x,y:Integer; col : Integer);
var i : Integer;
begin
  GotoXY(A[1].x,A[1].y); TextColor(0); Write(snake);
  For i := 1 to N-1 do begin A[i].x:=A[i+1].x; A[i].y:=A[i+1].y; end;
  A[N].x:=x; A[N].y:=y;
  If Crazy then TextColor(Random(15)+1)
           else TextColor(col);
  GotoXY(x,y); Write(snake); Delay(time);
end;

Procedure goo;
var Key, cur : char;
    x, y : Integer;
begin
  GotoXY(1,50);
  Write('"1..9,0" - colour change, "`" - crazy colour mod, "-" and "=" snake long');
  CursorOff;
  Randomize;
  NewFood;
  time:=50;
  Score:=0;
  Crazy := True;
  N:=InitLen;
  col:=15;
  x:=21;
  y:=21;
  Repeat
    If KeyPressed then
    begin
      Key := Readkey;
      If ord(Key) = 0 then Cur := ReadKey
                      else Case Key of
                               '1' : begin col:=1; Crazy:=False; end;
                               '2' : begin col:=2; Crazy:=False; end;
                               '3' : begin col:=3; Crazy:=False; end;
                               '4' : begin col:=4; Crazy:=False; end;
                               '5' : begin col:=5; Crazy:=False; end;
                               '6' : begin col:=6; Crazy:=False; end;
                               '7' : begin col:=7; Crazy:=False; end;
                               '8' : begin col:=8; Crazy:=False; end;
                               '9' : begin col:=9; Crazy:=False; end;
                               '0' : begin col:=10; Crazy:=False; end;
                               '-' : If N > 2 then N:=N-1;
                               '=' : If N < MaxLen-1 then N:=N+1;
                               '`' : Crazy:=True;
                             end;


    end;
    Case ord(Cur) of
      72 : begin y:=y-1; If y=1 then y:=49; end;
      75 : begin x:=x-1; If x=1 then x:=79; end;
      77 : begin x:=x+1; If x=80 then x:=2; end;
      80 : begin y:=y+1; If y=50 then y:=2; end;
    end;

    Debug(x,y);
    If (fx=x)and(fy=y) then NewFood;
    draw(x,y,col);


  Until Key = #27;
end;

Begin
 Clrscr;

 goo;

 CursorOn;
End.