# What, if any, is the term for a node whose children are all leaf nodes?

More specifically, I'm interested to know if there is a term that describes a tree node that meets two conditions: - It has >= one child - Any children that it has are all leaf nodes.

• Maybe penultimate node? – orlp Jan 4 at 16:52

## 1 Answer

They are classified as nodes of height 1 by convention in the case of a rooted tree.

The height of a node $$N$$ is the number of edges on the longest downward simple path from $$N$$ to a leaf, according to Introduction to Algorithms by CLRS as well as the Wikipedia entry.

You might want to use penultimate nodes as suggested by Orlp. Please note some papers define a penultimate node slight differently on general graphs as a nonleaf node that is adjacent to a leaf node. For example, Patrolling Games.