program feigenbaum;

{$I grbs.bic}

var xe, xa, xd:real;
    x, a:real;
    i, j:integer;
    wert:real;
    text:string[5];


begin
Clrscr;
write('Startwert      ');
readln(xa);
write('Zielwert       ');
readln(xe);
InitGraphic;

DrawLineDirect(42,10,42,10+165);
for i:=1 to 3 do
    begin
      DrawLineDirect(39,10+55*(i-1),42,10+55*(i-1));
      wert:=3.0-i; str(wert:2:0,text); DrawText(20,10+55*(i-1)-1,1,text)
    end;
DrawLineDirect(42,175,42+500,175);
for i:=1 to 11 do
    begin
      DrawLineDirect(42+50*(i-1),175,42+50*(i-1),175-3);
      wert:=xa+(i-1)*(xe-xa)/10; str(wert:4:2,text); DrawText(42+50*(i-1)-10,185,1,text)
    end;

xd:=(xe-xa)/500;
for i:=0 to 500 do
    begin
      x:=xa+xd*i;
      a:=0.5;
      for j:=-30 to 100 do
          begin
            a:=x*a*(1-a);
            if a<-1 then begin a:=-1; j:=100 end;
            if a>2  then begin a:= 2; j:=100 end;
            if j>0 then dp(i+42,120-round(55*a))
          end;
    end;

 readln;
 LeaveGraphic;

end.