Binary Search Trees maintain an ordered invariant: for every node, left child values are strictly smaller and right child values are strictly greater. Master search, insertion, node deletion, and BST validation in C++.
BST Invariant: Left subtree values < Node value < Right subtree values.
In-Order Sort Property: Traversing a valid BST in-order produces elements in strictly ascending sorted order.
Node Deletion (3 Cases): Leaf node (remove), single child (bypass), two children (replace with in-order successor).
Balanced BSTs: AVL and Red-Black trees auto-rotate to enforce O(log N) height limits.