What are the differences between a Binary Search Tree and a HashMap?

What are the differences between a Binary Search Tree and a HashMap?

A Binary Search Tree (BST) is a data structure that maintains sorted data and allows for efficient searching, insertion, and deletion. A HashMap, on the other hand, uses a hash function to map keys to values, providing average-case constant time complexity for these operations.

Which one is better for searching?

For searching, a HashMap is generally faster due to its average O(1) time complexity, while a BST has an average time complexity of O(log n). However, a BST maintains order, which can be beneficial for certain operations.

What about memory usage?

HashMaps typically use more memory due to the need for storing the hash table and handling collisions. BSTs use less memory but can become unbalanced, leading to inefficient operations.

Can you give me an example of when to use each?

Use a HashMap when you need fast lookups and don't require order. Use a BST when you need to maintain sorted data and perform range queries.