program zmeika;
  uses crt;
  type
  spoint=record
x:integer;
y:integer;
  end;
  const
  maxwidth=15;
var
  width:integer;
  e:spoint;
  snakebody:array[1..maxwidth] of spoint;
  i, nx,ny:integer;
  v:byte;
  gameover:boolean;
  key:char;
  function checknext(x:integer;y:integer):boolean;
var
  isset:boolean;
  i:integer;
begin
  isset:=true;
for i:=1 to width do
begin 
if (x=snakebody[i].x) and (y=snakebody[i].y) then
  isset:=false;
  end;
if isset then
begin 
if (x<=0) or (y<=0) or (x>=80) or (y>=25)then
  isset:=false;
  end;
checknext:=isset;
  end;{ᮧ¤*св Ґ¤г ** Ї®«Ґ}
procedure neweat;
begin
  e.x:=random(78)+2;
  e.y:=random(23)+2;
 
  while (not checknext(e.x,e.y)) do
begin
  e.x:=random(78)+2;
  e.y:=random(23)+2;
  end;
  end;
 
procedure movesnake (x,y:integer);
var
  i:integer;
begin
for i:=1 to width do
begin
  snakebody[i]:=snakebody[i+1];
end;
 
  snakebody[width].x:=x;
  snakebody[width].y:=y;
if (x=e.x) and (y=e.y) then 
begin
  width:=width+1;
  snakebody[width].x:=x;
  snakebody[width].y:=y;
  neweat;
end;
end;
{*****main program*****}
begin
  textbackground(3);
clrscr;
  textcolor(1);
  gotoxy(33,10);
write ('*****SNAKE*****');
  gotoxy(20,12);
write ('press W to go up');
  gotoxy(20,14);
write('press A to go left');
  gotoxy(20,16);
write('press D to go right');
  gotoxy(20,18);
write('press S to go down');
  gotoxy(27,22);
write('*****PRESS ENTER TO START*****');
  readln;
clrscr;
  gameover:=false;
 
  width:=4;
  snakebody[1].x:=1;
  snakebody[1].y:=1;
  snakebody[2].x:=2;
  snakebody[2].y:=1;
  snakebody[3].x:=3;
  snakebody[3].y:=1;
  snakebody[4].x:=4;
  snakebody[4].y:=1;
clrscr;
   v:=1;
   randomize;
   neweat;{ᮧ¤*с¬ Ґ¤г}
   while (width<maxwidth) do 
begin
if (keypressed) then
begin
   key:=readkey; 
   case key of
'w':begin if v=4 then continue; v:=3; end;{up}
's':begin if v=3 then continue; v:=4; end;{down}
'a':begin if v=1 then continue; v:=2; end;{left}
'd':begin if v=2 then continue; v:=1; end;{rigth}
#27:break; {exit}
end;
end;
clrscr;
 
   case v of
   1:begin nx:=snakebody[width].x+1;
   ny:=snakebody[width].y;end;{rigth}
   2:begin nx:=snakebody[width].x-1;
   ny:=snakebody[width].y;end;{left}
   3:begin nx:=snakebody[width].x;
   ny:=snakebody[width].y-1; end;{up}
   4:begin nx:=snakebody[width].x;
   ny:=snakebody[width].y+1;end;{down}
end;
 
if (not checknext(nx,ny)) then
begin
  gameover:=true;
 
  break;
end;
  movesnake(nx,ny);
  gotoxy(e.x,e.y);
  write('o'); 
for i:=1 to width-1 do
begin {
  gotoxy(snakebody[i].x,snakebody[i].y);
  textbackground(2);
  textcolor(15);
  write('o');
end;
  gotoxy (snakebody[width].x,snakebody[i].y);
  textcolor(4);
  write('o');
  gotoxy(80,25);
  delay(200)
end;
clrscr;
if (gameover) then 
begin
  textcolor(4);
  gotoxy(30,12);
  writeln('*****GAME OVER!*****');
end
else
begin
  textcolor(11);
  gotoxy(35,12);
  writeln('*****YOU WIN!*****') ;
end;
  textcolor(15);
  gotoxy(25,20);
  writeln('*****PRESS ENTER FOR EXIT!*****');
  readln;
end.