public void Add(T data)
{
lock (_synchRoot)
{
bool dataAdded = true;
if (_count == 0)
{
_root = new LinkedAvlTreeNode <T>(data);
}
else
{
_root.AddData(data, out _root, out dataAdded);
}
if (dataAdded)
{
_count++;
}
}
}
private bool AddChildRight(T data, out LinkedAvlTreeNode <T> node, out bool added)
{
bool subTreeHeightIncreased = false;
if (_right == null)
{
LinkedAvlTreeNode <T> child = new LinkedAvlTreeNode <T>(data);
_right = child;
child._previous = this;
child._next = this._next;
if (this._next != null)
{
this._next._previous = child;
}
this._next = child;
added = true;
if (_balance == 0)
{
_balance = 1;
}
else
{
System.Diagnostics.Debug.Assert(_balance == -1);
_balance = 0;
}
node = this;
return(_balance != 0);
}
else
{
subTreeHeightIncreased = _right.AddData(data, out _right, out added);
}
if (!subTreeHeightIncreased)
{
node = this;
return(false);
}
// the subtree height has changed!
if (_balance < 0) // the tree is balanced in a way that it has more children that are smaller
{
_balance = 0; // now the tree is balanced
node = this;
return(false);
}
else if (_balance == 0)
{
_balance = 1; // the tree is now unbalanced but still ok
node = this;
return(true);
}
else //we have to reestablish the order criterion of the tree
{
if (_right._balance == 1) // single rotation
{
RotateRight(out node);
node._balance = 0;
_balance = 0;
}
else // double rotation
{
DoubleRotateRight(out node);
AdjustBalance(node);
}
return(false);
}
}
/// <summary>
/// add a child whose value is smaller than the current data item
/// </summary>
/// <param name="child"></param>
private bool AddChildLeft(T data, out LinkedAvlTreeNode <T> node, out bool added)
{
bool subTreeHeightIncreased = false;
if (_left == null) // there is no smaller subtree!
{
LinkedAvlTreeNode <T> child = new LinkedAvlTreeNode <T>(data);
_left = child;
child._next = this;
child._previous = this._previous;
if (this._previous != null)
{
this._previous._next = child;
}
this._previous = child;
node = this;
added = true;
if (_balance == 0) // if the tree was balanced before, it is now longer on the left side
{
_balance = -1;
}
else // if it was longer on the right side!
{
System.Diagnostics.Debug.Assert(_balance == 1);
_balance = 0;
}
return(_balance != 0);
}
else
{
subTreeHeightIncreased = _left.AddData(data, out _left, out added);
}
if (!subTreeHeightIncreased)
{
node = this;
return(false);
}
// the subtree height has changed!
if (_balance > 0) // the tree is balanced in a way that it has more children that are bigger
{
_balance = 0; // now the tree is balanced
node = this;
return(false);
}
else if (_balance == 0)
{
_balance = -1; // the tree is now unbalanced but still ok
node = this;
return(true);
}
else //we have to reestablish the order criterion of the tree
{
if (_left._balance == -1) // single rotation
{
_left._balance = 0;
_balance = 0;
RotateLeft(out node);
}
else // double rotation
{
DoubleRotateLeft(out node);
AdjustBalance(node);
}
return(false);
}
}
