Book Image

The Complete Rust Programming Reference Guide

By : Rahul Sharma, Vesa Kaihlavirta, Claus Matzinger
Book Image

The Complete Rust Programming Reference Guide

By: Rahul Sharma, Vesa Kaihlavirta, Claus Matzinger

Overview of this book

Rust is a powerful language with a rare combination of safety, speed, and zero-cost abstractions. This Learning Path is filled with clear and simple explanations of its features along with real-world examples, demonstrating how you can build robust, scalable, and reliable programs. You’ll get started with an introduction to Rust data structures, algorithms, and essential language constructs. Next, you will understand how to store data using linked lists, arrays, stacks, and queues. You’ll also learn to implement sorting and searching algorithms, such as Brute Force algorithms, Greedy algorithms, Dynamic Programming, and Backtracking. As you progress, you’ll pick up on using Rust for systems programming, network programming, and the web. You’ll then move on to discover a variety of techniques, right from writing memory-safe code, to building idiomatic Rust libraries, and even advanced macros. By the end of this Learning Path, you’ll be able to implement Rust for enterprise projects, writing better tests and documentation, designing for performance, and creating idiomatic Rust code. This Learning Path includes content from the following Packt products: • Mastering Rust - Second Edition by Rahul Sharma and Vesa Kaihlavirta • Hands-On Data Structures and Algorithms with Rust by Claus Matzinger
Table of Contents (29 chapters)
Title Page
Copyright
About Packt
Contributors
Preface
Index

Hashing


The birthday paradox is a well-known phenomenon; two people share this special day that year, seemingly often, and we still get excited when it happens. Statistically speaking, the probability of meeting someone like this is really high, since in a room of just 23 people, the probability is already at 50%. While this may be an interesting fact, why is this introducing a section about hashing?

Birthdays can be considered a hash function—although a bad one. Hash functions are functions that map one value onto another value of a fixed size, like combining the day and month of a birthday into u64, shown as follows:

fn bd_hash(p: &Person) -> u64 {
    format!("{}{}", p.day, p.month) as u64
} 

This function will prove very ineffective indeed, shown as follows:

  • It is very hard to find out someone's birthday deterministically without asking them
  • The space is limited to 366 unique values, which also makes collisions very likely
  • They are not evenly distributed across the year

What makes a...