How Do HashMaps Work Under the Hood? (putting together a toy implementation in Rust to understand performance optimization, collisions, and time complexities)

HashMaps are incredibly convenient, but treating them like a magical black box can make it easy to overlook where their performance comes from. In this article, I explain how HashMaps work using a simple implementation in Rust. I go through hash collisions and linear probing, why primary clustering hurts performance, load factors, resizing, and more. The implementation is intentionally simplified, but it gives a good picture of what's actually happening underneath a HashMap. Let me know your thoughts or any feedback you have! All writing, illustrations, and code are my own. AI was used to clean up wording and catch grammatical mistakes. submitted by /u/PastEar9661 [link] [留言]