private NodeMeta SwapWithAdjacent(NodeMeta meta, Side side)
{
Side otherSide = OtherSide(side);
NodeMeta adjacentMeta = Adjacent(side, meta);
Node adjacent = adjacentMeta.Node;
Node toBeReplaced = meta.Node;
Node adjacentParent = adjacentMeta.ParentMeta.Node;
adjacentParent[otherSide] = adjacent[side];
// Swap the nodes.
// Cache the children of item to be replaced.
Node child = adjacent[side];
// Adjacent takes place of node to be removed.
meta.ReplaceNode(adjacent);
meta.ParentMeta.Node[meta.SideFromParent] = adjacent;
adjacent[side] = toBeReplaced[side];
adjacent[otherSide] = toBeReplaced[otherSide];
// Put node to be replaced in adjacent spot
adjacentParent[otherSide] = toBeReplaced;
toBeReplaced[side] = child;
toBeReplaced[otherSide] = null; // This is null, that is how we know it is the leaf
adjacentMeta.ReplaceNode(toBeReplaced);
// Swap the color
Color temp = toBeReplaced.Color;
toBeReplaced.Color = adjacent.Color;
adjacent.Color = temp;
if (child == null)
{
// We have found the node to remove. Replace it with a sentinal
SentinelNode sentinel = new SentinelNode(toBeReplaced.Color);
adjacentParent[otherSide] = sentinel;
return(new NodeMeta(adjacentMeta.ParentMeta, sentinel, adjacentMeta.SideFromParent, adjacentMeta.Sibling));
}
else
{
return(SwapWithAdjacent(adjacentMeta, side));
}
}
private NodeMeta SwapWithAdjacent(NodeMeta meta, Side side)
{
Side otherSide = OtherSide(side);
NodeMeta adjacentMeta = Adjacent(side, meta);
Node adjacent = adjacentMeta.Node;
Node toBeReplaced = meta.Node;
Node adjacentParent = adjacentMeta.ParentMeta.Node;
// Swap the nodes.
// Cache the children of item to be replaced.
Node child = adjacent[side];
bool parentChildSwap = toBeReplaced[side] == adjacent;
// Adjacent takes place of node to be removed.
meta.ReplaceNode(adjacent);
if (meta.ParentMeta == null)
{
root = adjacent;
}
else
{
meta.ParentMeta.Node[meta.SideFromParent] = adjacent;
}
if (!parentChildSwap)
{
adjacent[side] = toBeReplaced[side];
}
adjacent[otherSide] = toBeReplaced[otherSide];
// Put node to be replaced in adjacent spot
if (parentChildSwap)
{
adjacent[otherSide] = toBeReplaced;
}
else
{
adjacentParent[otherSide] = toBeReplaced;
}
toBeReplaced[side] = child;
toBeReplaced[otherSide] = null; // This is null, that is how we know it is the leaf
adjacentMeta.ReplaceNode(toBeReplaced);
// Swap the color
Color temp = toBeReplaced.Color;
toBeReplaced.Color = adjacent.Color;
adjacent.Color = temp;
if (meta.ParentMeta == null)
{
adjacent.Color = Color.Black;
}
if (child == null)
{
// We have found the node to remove. Replace it with a sentinal
return(adjacentMeta);
}
else
{
return(SwapWithAdjacent(adjacentMeta, side));
}
}