Traversal Overview
Binary search trees (BSTs) support efficient data retrieval. Traversal operations involve visiting each node in a specific order, crucial for searches, sorting, and understanding tree structure.
In-Order Traversal
In-order traversal guarantees ascending order visits in BSTs. It starts left, visits the node, then moves right. It's a depth-first strategy, revealing the sorted sequence inherent in BSTs.
Pre-Order Importance
Pre-order traversal visits the current node before its children. It's useful for copying the tree or expressing its structure in a compact form, like serialization for network transmission.
Post-Order Usage
Post-order traversal visits children before the node itself. Ideal for deletion scenarios, as it allows nodes to be removed after ensuring their descendants are processed.
Level-Order Traversal
Unlike depth-first strategies, level-order processes nodes level by level. It uses a queue and is synonymous with Breadth-First Search (BFS), instrumental for shortest-path tree problems.
Morris Traversal Method
Morris traversal achieves in-order traversal without recursion or a stack, by temporary links called 'threads'. It's space-efficient, using O(1) memory unlike typical O(h) with h as tree height.
Traversal Complexity
All standard BST traversals have O(n) time complexity, as each node is visited once. However, auxiliary space varies: O(h) for recursive depth-first, O(n) for level-order, and O(1) for Morris.