Initial import

mdl/m_quicksort.pas

@@ -0,0 +1,117 @@
+{$I M_OPS.PAS}
+
+Unit m_QuickSort;
+
+Interface
+
+Const
+  mdlMaxSortSize = 5000;
+
+Type
+  TSortMethod = (qAscending, qDescending);
+
+  PQuickSortRec = ^TQuickSortRec;
+  TQuickSortRec = Record
+    Name : String;
+    Ptr  : LongInt;
+  End;
+
+  TQuickSort = Class
+    Total : Word;
+    Data  : Array[1..mdlMaxSortSize] of PQuickSortRec;
+
+    Constructor Create;
+    Destructor  Destroy; Override;
+
+    Function    Add  (Name: String; Ptr: LongInt) : Boolean;
+    Procedure   Sort (Left, Right: Word; Mode: TSortMethod);
+    Procedure   Clear;
+  End;
+
+Implementation
+
+Constructor TQuickSort.Create;
+Begin
+  Inherited Create;
+
+  Total := 0;
+End;
+
+Destructor TQuickSort.Destroy;
+Begin
+  Clear;
+
+  Inherited Destroy;
+End;
+
+Procedure TQuickSort.Clear;
+Var
+  Count : Word;
+Begin
+  For Count := 1 to Total Do
+    Dispose (Data[Count]);
+
+  Total := 0;
+End;
+
+Function TQuickSort.Add (Name: String; Ptr: LongInt) : Boolean;
+Begin
+  Result := False;
+
+  Inc (Total);
+  New (Data[Total]);
+
+  If Data[Total] = NIL Then Begin
+    Dec (Total);
+    Exit;
+  End;
+
+  Data[Total]^.Name := Name;
+  Data[Total]^.Ptr  := Ptr;
+
+  Result := True;
+End;
+
+Procedure TQuickSort.Sort (Left, Right: Word; Mode: TSortMethod);
+Var
+  Temp   : PQuickSortRec;
+  Pivot  : TQuickSortRec;
+  Lower  : Word;
+  Upper  : Word;
+  Middle : Word;
+Begin
+  If Total = 0 Then Exit;
+
+  Lower  := Left;
+  Upper  := Right;
+  Middle := (Left + Right) DIV 2;
+  Pivot  := Data[Middle]^;
+
+  Repeat
+    Case Mode of
+      qAscending : Begin
+            While Data[Lower]^.Name < Pivot.Name Do Inc(Lower);
+            While Pivot.Name < Data[Upper]^.Name Do Dec(Upper);
+          End;
+      qDescending : Begin
+            While Data[Lower]^.Name > Pivot.Name Do Inc(Lower);
+            While Pivot.Name > Data[Upper]^.Name Do Dec(Upper);
+          End;
+    End;
+
+    If Lower <= Upper Then Begin
+      Temp        := Data[Lower];
+      Data[Lower] := Data[Upper];
+      Data[Upper] := Temp;
+
+      Inc (Lower);
+      Dec (Upper);
+    End;
+
+  Until Lower > Upper;
+
+  If Left  < Upper Then Sort(Left,  Upper, Mode);
+  If Lower < Right Then Sort(Lower, Right, Mode);
+End;
+
+End.