type
  TMyArray= array of cardinal;

function Divide(x, y: cardinal): cardinal;
begin;
  while y and 1=0 do begin;
    x:=x shr 1;
    y:=y shr 1;
    end;
  Result:=1;
  while y<>1 do begin;
    Result:=Result*y;
    y:=y*y;
    end;
  Result:=Result*x;
  end;

procedure Calculate(a: TMyArray);
var
  x: cardinal;
  i, j, len: integer;
begin;
  len:=Length(a);
  x:=1; j:=-1;
  for i:=0 to len-1 do begin;
    if a[i]=0 then begin;
      if j>=0 then begin;
        j:=len;
        break;
        end;
      j:=i;
      end
    else x:=x*a[i];
    end;
  if j>=0 then begin;
    for i:=0 to len-1 do a[i]:=0;
    if j<len then a[j]:=x;
    end
  else for i:=0 to len-1 do a[i]:=Divide(x, a[i]);
  end;

type
  TMyArray= array of cardinal;

procedure Multiply(var x, e: cardinal; y: cardinal);
var
  m, d: cardinal;
begin;
  m:=1;
  d:=0;
  while y and m=0 do begin;
    m:=m+m;
    d:=d+1;
    end;
  x:=x*(y shr d);
  e:=e+d;
  end;

function Divide(x, e, y: cardinal): cardinal;
var
  m, d: cardinal;
begin;
  m:=1;
  d:=0;
  while y and m=0 do begin;
    m:=m+m;
    d:=d+1;
    end;
  y:=y shr d;
  e:=e-d;
  if e<8*SizeOf(x) then begin;
    while y<>1 do begin;
      x:=x*y;
      y:=y*y;
      end;
    Result:=x shl e;
    end
  else Result:=0;
  end;

procedure Calculate(a: TMyArray);
var
  x, e: cardinal;
  i, j, len: integer;
begin;
  len:=Length(a);
  x:=1; e:=0; j:=-1;
  for i:=0 to len-1 do begin;
    if a[i]=0 then begin;
      if j>=0 then begin;
        j:=len;
        break;
        end;
      j:=i;
      end
    else Multiply(x, e, a[i]);
    end;
  if j>=0 then begin;
    for i:=0 to len-1 do a[i]:=0;
    if j<len then a[j]:=Divide(x, e, 1);
    end
  else for i:=0 to len-1 do a[i]:=Divide(x, e, a[i]);
  end;

procedure TForm1.Button1Click(Sender: TObject);
var
  a: TMyArray;
begin;
  SetLength(a, 4);
  a[0]:=1;
  a[1]:=7;
  a[2]:=3;
  a[3]:=4;
  Memo1.Lines.Add(Format('%d %d %d %d', [a[1]*a[2]*a[3], a[0]*a[2]*a[3], a[0]*a[1]*a[3], a[0]*a[1]*a[2]]));
  Calculate(a);
  Memo1.Lines.Add(Format('%d %d %d %d', [a[0], a[1], a[2], a[3]]));
  end;