An extended binary tree is a binary tree in which special nodes are added wherever a null subtree was present in the original tree so that each node in the original tree (except the root vertex) has vertex degree three (Knuth 1997, p. 399).
Extended Binary Tree
See also
Binary TreeExplore with Wolfram|Alpha
References
Knuth, D. E. The Art of Computer Programming, Vol. 1: Fundamental Algorithms, 3rd ed. Reading, MA: Addison-Wesley, 1997.Referenced on Wolfram|Alpha
Extended Binary TreeCite this as:
Weisstein, Eric W. "Extended Binary Tree." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/ExtendedBinaryTree.html