// Copyright (c) 1998-1999 Matra Datavision
// Copyright (c) 1999-2012 OPEN CASCADE SAS
//
// The content of this file is subject to the Open CASCADE Technology Public
// License Version 6.5 (the "License"). You may not use the content of this file
// except in compliance with the License. Please obtain a copy of the License
// at http://www.opencascade.org and read it completely before using this file.
//
// The Initial Developer of the Original Code is Open CASCADE S.A.S., having its
// main offices at: 1, place des Freres Montgolfier, 78280 Guyancourt, France.
//
// The Original Code and all software distributed under the License is
// distributed on an "AS IS" basis, without warranty of any kind, and the
// Initial Developer hereby disclaims all such warranties, including without
// limitation, any warranties of merchantability, fitness for a particular
// purpose or non-infringement. Please see the License for the specific terms
// and conditions governing the rights and limitations under the License.

// SortTools_QuickSort.gxx 
// cree le 04/11/91 par ASI
// Reference : Software Conponents with ADA, Grady Booch.

inline void Exchange(Item& Left, Item& Right)
{  
  Item Temp = Left;
  Left = Right;
  Right = Temp;
}

static void SortRecursive(Array& TheArray,
			  const Comparator& Comp,
			  const Standard_Integer Left, 
			  const Standard_Integer Right)
{
  Item Pivot;
  Standard_Integer Front, Back, Middle;
  
  if(Left < Right) {
    Middle = (Left + Right) / 2;
    if(Comp.IsLower(TheArray(Middle), TheArray(Left))) {
      Exchange(TheArray(Middle), TheArray(Left));
    }
    if(Comp.IsLower(TheArray(Right), TheArray(Left))) {
      Exchange(TheArray(Right), TheArray(Left));
    }
    if(Comp.IsLower(TheArray(Right), TheArray(Middle))) {
      Exchange(TheArray(Right), TheArray(Middle));
    }
    Pivot = TheArray(Middle);
    Exchange(TheArray(Middle), TheArray(Right - 1));
    Front = Left + 1;
    Back = Right - 1;
    if(Back != TheArray.Lower()) {
      Back = Back - 1;
    }
    for(;;) {
      while (Comp.IsLower(TheArray(Front), Pivot)) {
	Front = Front + 1;
      }
      while (Comp.IsLower(Pivot, TheArray(Back))) {
	Back = Back - 1;
      }
      if(Front <= Back) {
	if(Front == TheArray.Upper()) return;
	if(Back == TheArray.Lower()) return;  
	Exchange(TheArray(Front), TheArray(Back));
	Front = Front + 1;
	Back = Back - 1;
      }
      if(Front > Back) break;
    }
    SortRecursive(TheArray, Comp, Left, Back);
    SortRecursive(TheArray, Comp, Front, Right);
  }
}

void SortTools_QuickSort::Sort(Array& TheArray, 
			  const Comparator& Comp)
{
  SortRecursive(TheArray, Comp, TheArray.Lower(), TheArray.Upper()); 
}