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Rodion Efremov commented on COLLECTIONS-479: -------------------------------------------- Hello everybody! I wasn't able to work on this one after all. However, I started today from scratch and have a progress on counted AVL-tree: insert, lookup and deletion implemented. Just lacks the actual counts needed for making it an order statistic tree. Question: what interfaces should I implement? java.util.Set seems like natural choice, but there might be more. What would be your opinion on this one? > An Order Statistic Tree > ----------------------- > > Key: COLLECTIONS-479 > URL: https://issues.apache.org/jira/browse/COLLECTIONS-479 > Project: Commons Collections > Issue Type: New Feature > Reporter: Ajo Fod > Priority: Minor > Fix For: 4.x > > Attachments: COLLECTIONS-479.patch, NodeExistsException.java, > RedBlackBST.java > > > An order statistic tree http://en.wikipedia.org/wiki/Order_statistic_tree > provides two useful properties. The ability to rank arbitrary keys relative > to keys existing in the tree AND the ability to retrieve elements from the > tree with the given rank. > This can be used to find the percentile rank of a key for example. > This functionality is not yet provided yet by any of the major libraries > AFAIK. -- This message was sent by Atlassian JIRA (v6.3.4#6332)