private AVL_Node <T> Balance(AVL_Node <T> x)
{
x.Update();
if (x.Balance_Factor > 1)
{
if (x.Rigth.Balance_Factor <= 0)
{
x.Rigth = Rotate(x.Rigth, Direction.Rigth);
}
x = Rotate(x, Direction.Left);
}
else
if (x.Balance_Factor < -1)
{
if (x.Left.Balance_Factor >= 0)
{
x.Left = Rotate(x.Left, Direction.Left);
}
x = Rotate(x, Direction.Rigth);
}
x.Update();
return(x);
}
private AVL_Node <T> Rotate(AVL_Node <T> x, Direction direction)
{
AVL_Node <T> y;
if (direction == Direction.Left) // left
{
if (x == null || x.Rigth == null)
{
return(x);
}
y = x.Rigth;
x.Rigth = y.Left;
y.Left = x;
}
else // right
{
if (x == null || x.Left == null)
{
return(x);
}
y = x.Left;
x.Left = y.Rigth;
y.Rigth = x;
}
x.Update();
y.Update();
return(y);
}
private AVL_Node <T> Insert(AVL_Node <T> x, T item)
{
if (x == null)
{
x = new AVL_Node <T> ();
x.Key = item;
x.Height = 1;
x.Size = 1;
x.Left = null;
x.Rigth = null;
Count++;
}
else
{
if (item.CompareTo(x.Key) == 0)
{
return(x);
}
if (item.CompareTo(x.Key) < 0)
{
x.Left = Insert(x.Left, item);
}
else
{
x.Rigth = Insert(x.Rigth, item);
}
x = Balance(x);
}
return(Balance(x));
}
public AVL_Node <T> Contains(T item)
{
AVL_Node <T> x = C_Root;
for (; ;)
{
if (x == null)
{
return(null);
}
if (item.CompareTo(x.Key) == 0)
{
return(x);
}
x = item.CompareTo(x.Key) < 0 ? x.Left : x.Rigth;
}
}