Binary search is a cheap way of getting an O(log n) .contains() without the additional logic of proper AVL/RedBlack trees (or hashmaps). If you need to check wh

Binary search is a cheap way of getting an O(log n) .contains() without the additional logic of proper AVL/RedBlack trees (or hashmaps). If you need to check whether an element is a member of a set many times, the once-off O(n log n) setup cost is no worse than any other trees (it is worse than hashmaps but those have other downsides).