顽皮的小球

感谢世外苏子恒同学提供

 

uses crt;

var

  x,y,xd,yd:shortint;

 

procedure intro;

begin

  clrscr;

  writeln;

  writeln;

  writeln;

  writeln;

  writeln;

  writeln('Naughty ball':46);

  writeln('--by suziheng':55);

  writeln;

  writeln;

  writeln('Press CTRL+C to exit the program.':57);

  writeln;

  writeln;

  writeln('Press Enter to start the program.':57);

  readln;

end;

 

begin

  xd:=1;

  yd:=1;

  x:=2;

  y:=2;

  intro;

  cursoroff;

  while true do begin

    x:=x+xd;

    y:=y+yd;

    clrscr;

    gotoxy(x,y);

    write('O');

    delay(100);

    if (x=80) or (x=1) then xd:=-xd;

    if (y=25) or (y=1) then yd:=-yd;

  end;

end.