// Level Order: like LILO
public IEnumerable <BiTreeNode <T> > LevelOrder(BiTreeNode <T> root)
{
if (root == null)
{
yield break;
}
var queue = new LinkedQueue <BiTreeNode <T> >();
queue.In(root);
while (!queue.IsEmpty())
{
var node = queue.Out();
yield return(node);
if (node.LeftChild != null)
{
queue.In(node.LeftChild);
}
if (node.RightChild != null)
{
queue.In(node.RightChild);
}
}
}
public HuffmanTreeNode(
T weight,
BiTreeNode <T> left_child,
BiTreeNode <T> right_child,
BiTreeNode <T> parent) : base(weight, left_child, right_child)
{
Parent = parent;
}
public BiTreeNode <T> InsertRight(T val, BiTreeNode <T> parent)
{
var tmp = new BiTreeNode <T>(val)
{
RightChild = parent.RightChild
};
parent.RightChild = tmp;
return(tmp);
}
public BiTreeNode <T> InsertLeft(T val, BiTreeNode <T> parent)
{
var tmp = new BiTreeNode <T>(val)
{
LeftChild = parent.LeftChild
};
parent.LeftChild = tmp;
return(tmp);
}
public BiTreeNode <T> DeleteRight(BiTreeNode <T> p)
{
if (p?.RightChild == null)
{
return(null);
}
var tmp = p.RightChild;
p.RightChild = null;
return(tmp);
}
public BiTreeNode <T> DeleteLeft(BiTreeNode <T> p)
{
if (p?.LeftChild == null) // p == null || p.LeftChild == null
{
return(null);
}
var tmp = p.LeftChild;
p.LeftChild = null;
return(tmp);
}
// LRD: first left subtree, then right subtree, finally root
public IEnumerable <BiTreeNode <T> > PostOrder(BiTreeNode <T> root)
{
if (root == null)
{
yield break;
}
foreach (var node in PostOrder(root.LeftChild))
{
yield return(node);
}
foreach (var node in PostOrder(root.RightChild))
{
yield return(node);
}
yield return(root);
}
public bool IsLeaf(BiTreeNode <T> p)
{
return((p != null) && (p.LeftChild == null) && (p.RightChild == null));
}
public BiTreeNode <T> GetRightChild(BiTreeNode <T> parent)
{
return(parent.RightChild);
}
public BiTreeNode <T> GetLeftChild(BiTreeNode <T> parent)
{
return(parent.LeftChild);
}
public BiTree(T val, BiTreeNode <T> left_child, BiTreeNode <T> right_child)
{
Head = new BiTreeNode <T>(val, left_child, right_child);
}
public BiTree(T val)
{
Head = new BiTreeNode <T>(val);
}
public BiTree()
{
Head = null;
}
