unit1.pas

本光盘是《Delphi 7应用教程》一书的配套光盘

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Label1: TLabel;
    Edit1: TEdit;
    Edit2: TEdit;
    Label2: TLabel;
    Edit3: TEdit;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}
Function  zh(k_fz,k_fm:Integer):Integer;  //自定义外层函数求组合数
var                                       //定义函数zh的变量
  fz,fm1,fm2:Integer;
Function  jc(k:Integer):Integer;        //内层函数求阶乘
var
  n1,n:Integer;                         //定义函数jc的变量
begin
  n:=1;
  for n1:=1 to k do
    n:=n*n1;
  jc:=n;
end;                                    //内部函数体结束
begin
  zh:=1;
  fz:=jc(k_fz);                   //调用内层子程序求组合数的分子部分
  fm1:=jc(k_fm);                  //调用内层子程序求组合数的分母部分
  fm2:=jc(k_fz-k_fm);
  zh:=fz div (fm1*fm2);     //由于组合数肯定是个整数，因此这里用整除形式
end;
procedure TForm1.Button1Click(Sender: TObject);
var
  m1,m2,m:Integer;
begin
  m1:=StrToInt(Edit1.Text);
  m2:=StrToInt(Edit2.Text);
  m:=zh(m2,m1);                   //调用组合函数zh求组合数
  Edit3.Text:=IntToStr(m);
end;

end.