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

void Shift(Array& TheArray, 
	   const Comparator& Comp, 
	   const Standard_Integer Left, const Standard_Integer Right)
{
  Item Temp = TheArray(Left);
  Standard_Integer Front = Left;
  Standard_Integer Back = Front * 2;
  while (Back <= Right) {
    if (Back < Right) {
      if(Comp.IsLower(TheArray(Back), TheArray(Back + 1))) {
	Back = Back + 1; 
      }
    }
    if(!Comp.IsLower(Temp, TheArray(Back))) break;
    TheArray(Front) = TheArray(Back);
    Front = Back;
    if(Front * 2 > TheArray.Upper()) break;
    Back = Front * 2; 
  }
  TheArray(Front) = Temp;
}

void SortTools_HeapSort::Sort(Array& TheArray, 
			      const Comparator& Comp)
{
  Item TempItem; 
  Standard_Integer Left;
  Standard_Integer Right;

  Left = ((TheArray.Upper() - TheArray.Lower() + 1) / 2) + 1;
  Right = TheArray.Upper();
  while (Left > TheArray.Lower()) {
    Left = Left - 1;
    Shift(TheArray, Comp, Left, Right);
  }
  while (Right > TheArray.Lower()) {
    TempItem = TheArray(TheArray.Lower());
    TheArray(TheArray.Lower()) = TheArray(Right);
    TheArray(Right) = TempItem;
    Right = Right - 1;
    Shift(TheArray, Comp, Left, Right);
  }
}