列如算出來的a值為-10,20,-40,50,7,-12 如何排序

vampire 你好 :    參考看看 :

function MySortAsc(List: TStringList; Index1, Index2: Integer): Integer;
begin
  Result := CompareValue(StrtoInt(List[Index1]),StrToInt(List[Index2]));
end;    function MySortDesc(List: TStringList; Index1, Index2: Integer): Integer;
begin
  Result := -MySortAsc(List,Index1,Index2);
end;    procedure TForm1.Button1Click(Sender: TObject);
var s : TStringList;
begin
  s := TStringList.Create;
  try
    s.CommaText := '-10,20,-40,50,7,-12';
    s.Sorted := False;
    s.CustomSort(MySortAsc); // 由小到大
    showmessage(s.CommaText);
    s.CustomSort(MySortDesc); // 由大到小
    showmessage(s.CommaText);
  finally
    s.Free;
  end;
end;

Note : 須增加 use Math. 發表人 - Mickey 於 2003/10/21 14:20:11

 
unit Unit1;    interface    uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;    type
  PMyList = ^AList;
  AList = record
    I: Integer;
  end;    type
  TForm1 = class(TForm)
    Memo1: TMemo;
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;    var
  Form1: TForm1;    implementation    {$R *.dfm}    function CompareNum(Item1, Item2: PMyList): Integer;
begin
    Result :=  Item1.I - Item2.I;
end;    procedure TForm1.FormCreate(Sender: TObject);
var
    tl:TList;
    a1:PMyList;
    i:integer;
begin
  try
    tl := Tlist.Create;
    New(a1);
    a1.I := -10;
    tl.Add(a1);
    New(a1);
    a1.I := -20;
    tl.Add(a1);
    New(a1);
    a1.I := 30;
    tl.Add(a1);
    New(a1);
    a1.I := 100;
    tl.Add(a1);
    New(a1);
    a1.I := -100;
    tl.Add(a1);        tl.Sort(@CompareNum);        for i:=0 to tl.Count -1 do
    begin
      a1 := tl.Items[i];
      memo1.Lines.Add(IntToStr(a1.I));
    end;
   finally
     tl.Free;
   end;
end;    end.    

上面是利用 TList 作排序的小範例,寫得有點亂,請包涵 另外寫一個 bubble sort,binary sort , Quick sort function 也是可以的 詳情請參考各大 Data Struct 書內範例

小至大
function CompareNum(Item1, Item2: Pointer): Integer;
begin
Result := Pointer(Item1) - Pointer(Item2);
end;

procedure TForm1.FormCreate(Sender: TObject);
var
tl:TList;
begin
tl := Tlist.Create;
tl.Add(Pointer(-10));
tl.Add(Pointer(-20));
tl.Add(Pointer(30));
tl.Add(Pointer(100));
tl.Add(Pointer(-100));
tl.Sort({@}CompareNum);
for i:=0 to tl.Count -1 do
begin
memo1.Lines.Add(IntToStr(Integer(tl.Items[i])));
end;
tl.Free;
end;

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