The document discusses the const keyword in C++ and balanced binary search trees. It describes three uses of const: 1) to prevent functions from modifying parameters, 2) to prevent class member functions from modifying member variables, and 3) to return constant references from functions. It then discusses balanced binary search trees, including degenerate trees, AVL trees which restrict height differences to 1, and fully balanced trees where all nodes have subtrees of equal height.

1. Class No.19 Data Structures http://ecomputernotes.com

15. Balanced Binary Tree http://ecomputernotes.com -1 0 1 0 0 0 0 -1 0 1 0 0 0 0 0 0 0