What are some real-world applications of AVL trees today?

search, insert, delete, min and max operations all run in O(logN). So, it has many use cases, all operations needs to have same time complexity, particularly look up intensive applications.

Trains in a railway system. I am not sure how IRCTC (Or, any other Railway system) implements it, but taking the fact into account that newer trains come up very few every year and the[code] struct train {};[/code] remains constant for a good period of time, an AVL implementation of this would be better than any other tree for searching. AVL trees are beneficial in the cases where you are designing some database where insertions and deletions are not that frequent but you have to frequently look-up for the items present in there.

There are as many applications of AVL tree as there are applications of set<>, TreeSet<>, etc. It provides you with the same interface as RB-tree which is used in implementation of standard libraries mentioned above. Actually, it is even faster than RB-tree, but requires one bit more memory to store additional info used for self-balancing.

search, insert, delete, min and max operations all run in O(logN). So, it has many use cases, all operations needs to have same time complexity, particularly look up intensive applications. Even though insertion is burden its easy for searching AVL is no longer used as Red-Black Tree over took AVL tree.