protected BinaryNode <T> Remove(BinaryNode <T> node)
{
if (node == default(BinaryNode <T>))
{
return(null);
}
this.Count--;
if (node.LeftChild == null && node.RightChild == null)
{
if (node.Parent == null)
{
this.Root = null;
}
else if (node.Parent.LeftChild == node)
{
node.Parent.LeftChild = null;
}
else
{
node.Parent.RightChild = null;
}
return(node.Parent);
}
BinaryNode <T> successer;
BinaryNode <T> parent;
if (node.LeftChild == null || node.RightChild == null)
{
successer = node.LeftChild ?? node.RightChild;
parent = node.Parent;
}
else
{
successer = node.RightChild;
while (successer.LeftChild != null)
{
successer = successer.LeftChild;
}
parent = successer.Parent;
}
if (node.Parent == null)
{
this.Root = successer;
successer.Parent = null;
}
else if (node.Parent.LeftChild == node)
{
node.Parent.LeftChild = successer;
successer.Parent = node.Parent;
}
else
{
node.Parent.RightChild = successer;
node.LeftChild.Parent = successer;
}
return(parent);
}
public void Clear()
{
this.Root = null;
this.Count = 0;
}
protected BinaryNode(T key, BinaryNode <T> parent)
{
this.Key = key;
this.Parent = parent;
}
public BinarySearchNode(T key, BinaryNode <T> parent, BinaryNode <T> childA, BinaryNode <T> childB) :
base(key, parent, childA, childB)
{
}
public BinarySearchNode(T key, BinaryNode <T> parent) : base(key, parent)
{
}
public override bool Remove(T item)
{
BinaryNode <T> node = Search(item);
if (node == null)
{
return(false);
}
BinaryNode <T> n = Remove(node);
if (n == null)
{
return(true);
}
BinaryNode <T> g;
BinaryNode <T> z;
int b;
for (BinaryNode <T> x = n.Parent; x != null; x = g)
{
g = x.Parent;
if (n.IsLeftChild)
{
if (x.Balance > 0)
{
z = x.RightChild;
b = z.Balance;
if (b < 0)
{
n = RotateRightLeft(x, z);
}
else
{
n = RotateRight(x, z);
}
}
else
{
if (x.Balance == 0)
{
x.Balance = 1;
break;
}
n = x;
n.Balance = 0;
continue;
}
}
else
{
if (x.Balance < 0)
{
z = x.LeftChild;
b = z.Balance;
if (b > 0)
{
n = RotateLeftRight(x, z);
}
else
{
n = RotateLeft(x, z);
}
}
else
{
if (x.Balance == 0)
{
x.Balance = -1;
break;
}
n = x;
n.Balance = 0;
continue;
}
}
n.Parent = g;
if (g != null)
{
if (g.LeftChild == x)
{
g.LeftChild = n;
}
else
{
g.RightChild = n;
}
if (b == 0)
{
break;
}
}
else
{
this.Root = n;
}
}
return(true);
}
public override BinaryNode <T> Insert(T key)
{
BinaryNode <T> node = base.Insert(key);
BinaryNode <T> z = node;
BinaryNode <T> g;
BinaryNode <T> n;
for (BinaryNode <T> x = z.Parent; x != null; x = z.Parent)
{
if (z.IsRightChild)
{
if (x.Balance > 0)
{
g = x.Parent;
n = z.Balance < 0 ? RotateRightLeft(x, z) : RotateLeft(x, z);
}
else
{
if (x.Balance < 0)
{
x.Balance = 0;
break;
}
x.Balance = 1;
z = x;
continue;
}
}
else
{
if (x.Balance < 0)
{
g = x.Parent;
n = z.Balance > 0 ? RotateLeftRight(x, z) : RotateRight(x, z);
}
else
{
if (x.Balance > 0)
{
x.Balance = 0;
break;
}
z = x;
x.Balance = -1;
continue;
}
}
n.Parent = g;
if (g != null)
{
if (g.LeftChild == x)
{
g.LeftChild = n;
}
else
{
g.RightChild = n;
}
break;
}
this.Root = n;
break;
}
return(node);
}
