u_form.pas

来自「很好地delphi书籍源码」· PAS 代码 · 共 87 行

unit U_form;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, Spin, ExtCtrls;

type
  TForm1 = class(TForm)
    CalcButton: TButton;
    RGroup: TRadioGroup;
    procedure CalcButtonClick(Sender: TObject);
  private
    { Private declarations }
  public
end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

function F1(n: word): word;
begin
  if n<=0 then exit
  else if n=1 then result:=1
  else Result:=n*F1(n-1);
end;

function F2(n: word): word;
var
  Loc_sum,i:word;
begin
  if n<=0 then exit;
  if n=1 then begin result:=1; exit; end;
  Loc_sum:=0;
  if n>1 then
  begin
    for i:=1 to n do
    Loc_sum:=Loc_sum+i;
  end;
  result:=F2(n-1)+Loc_sum ;
end;

function F3(n: word): word;
begin
  if n<=0 then exit;
  if n=1 then begin result:=1; exit; end;
  result:=F3(n-1)+F1(n) ;
end;

procedure TForm1.CalcButtonClick(Sender: TObject);
var
  Loc_st:string ;
  Loc_N:word;
begin
  case RGroup.ItemIndex of
  0:begin
      if InputQuery(RGroup.Items.Strings[0],'N=', Loc_st) then
      begin
        Loc_N:=StrToInt(Loc_st);
        Caption:=Format('%d!=%d',[Loc_N,F1(Loc_N)]);
      end;
    end;
  1:begin
       if InputQuery(RGroup.Items.Strings[1],'N=', Loc_st) then
       begin
         Loc_N:=StrToInt(Loc_st);
         Caption:=Format('S=%d',[F2(Loc_N)]);
       end;
     end;
   2:begin
       if InputQuery(RGroup.Items.Strings[1],'N=', Loc_st) then
       begin
          Loc_N:=StrToInt(Loc_st);
          Caption:=Format('S=%d',[F3(Loc_N)]);
       end;
     end;
  end;
end;


end.