# What is the name of the tree data structure where node weight equals the sum of all descendant nodes' weights?

What is the name of the tree data structure where node weight equals the sum of all descendant nodes' weights?

Example:

      15
/    \
10     5
/  \   / \
2    8 1   4

• What makes you think there is a name for it? The great thing about language is that it lets us describe and name things for ourselves -- there are many more good ideas than existing "names", and there's no reason to think that every good idea has to have a standard "name". – D.W. Jul 18 '18 at 18:14
• Maybe someone studied this before and gave a name, I just wanted to know if there is a name. If I know how people call it I can search it on web and study it. – ferit Jul 18 '18 at 18:14
• My standard advice is: figure out what you'd do with the "name", and then ask about that. If the name would help you research this to answer some question about the data structure, then ask that question. That way either someone responds with a name, or answers your question. But I don't find questions of the form "here is my data structure/algorithm, does it have a name?" very likely to be valuable to others in the future. – D.W. Jul 18 '18 at 18:16
• This looks like some type of Binary Tree but if you're asking for a specific condition where the descending nodes are equal to it's preceding node, then I don't think that has a specific name for that. – KingDuken Jul 18 '18 at 20:43
• Such trees are encountered in dynamic huffman/arithmetic coders. Never seen specific name for them though – Bulat Jul 24 '18 at 11:05