极快的正整数排序函数

实现原理: 对比二进制位.

---

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    Memo1: TMemo;
    procedure Button1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

type
  TIntArr = array of Integer;

{极快的正整数排序函数}
procedure IntSort(arr:TIntArr; low:Integer=0; high:Integer=-1; k:Cardinal=$80000000; c:Cardinal=1);
var
  i,j,x: Integer;
begin
  if high = -1 then high := Length(arr) -1;
  i := low;
  j := high;
  while (i < j) do
  begin
    while (arr[j] and k <> 0) and (i < j) do Dec(j);
    while (arr[i] and k = 0) and (i < j) do Inc(i);
    if i < j then
    begin
      x := arr[j];
      arr[j] := arr[i];
      arr[i] := x;
    end else begin
      if arr[j] and k <> 0 then Dec(i) else Inc(j);
      Break;
    end;
  end;
  if k > c then
  begin
    if low < i then IntSort(arr, low, i, k div 2);
    if j < high then IntSort(arr, j, high, k div 2);
  end;
end;

{测试}
procedure TForm1.Button1Click(Sender: TObject);
var
  MyArr: TIntArr;
  i: Integer;
  t: Int64;
begin
  SetLength(MyArr, MAXWORD);
  for i := Low(MyArr) to High(MyArr) do MyArr[i] := Random(MaxInt);
  
  t := GetTickCount;
  
  IntSort(MyArr); //调用排序函数
  
  Text := IntToStr(GetTickCount - t);

  Memo1.Clear;
  for i := 0 to Length(MyArr)-1 do
  begin
    if i mod 1000 = 0 then
      Memo1.Lines.Add(IntToStr(MyArr[i]));
  end;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  Memo1.Clear;
  Memo1.Align := alLeft;
  Memo1.ScrollBars := ssVertical;
end;

end.