function GetMaxOccur(s:string; var c:char):integer;
var i,n:integer;
    a: array[0..9] of integer;
begin
  for i:=0 to 9 do a[i]:=0;
  for i:=1 to length(s) do begin
    n:= pos(s[i],'0123456789');
    if n > 0 then
      a[n-1]:=a[n-1] 1;
  end;
  c:='0';
  Result:=a[0];
  for i:=0 to 9 do
    if a[i] > Result then begin
      c:=chr(i 48);
      Result:=a[i];
    end;
end;
procedure TEnterForm.Button1Click(Sender: TObject);
var n:integer;
  c:char;
begin
  n:=GetMaxOccur('1122233333444556778890',c);
  showmessage('最多者為' c ' 共' inttostr(n) '個');
end;