Introduction

Welcome to Rust 101 - a comprehensive collection of 101 exercises designed to take you from Rust beginner to confident Rustacean.

What Makes This Different?

Unlike micro-exercises like Rustlings, these exercises are:

• Substantial: Each exercise builds something real and satisfying
• Progressive: Concepts build naturally on each other
• Comprehensive: Forces you to use every Rust feature in context
• Practical: Skills transfer directly to real-world Rust programming

Structure

The 101 exercises are organized into 10 phases:

1. Foundations (1-15): Basic syntax, ownership, simple collections
2. Intermediate Collections (16-30): Advanced collection usage, patterns
3. Error Handling & I/O (31-40): Result, Option, file operations
4. Ownership Deep Dive (41-50): Lifetimes, borrowing, Cow
5. Smart Pointers (51-65): Box, Rc, RefCell, Arc, Weak
6. Trait System (66-75): Traits, generics, trait objects
7. Advanced Patterns (76-85): Custom iterators, builder pattern, typestate
8. Concurrency (86-92): Threads, channels, sync primitives
9. Real-World Algorithms (93-100): Graph algorithms, DP, search
10. Capstone (101): Complete compiler + VM with event loop

How to Use This Book

1. Read the exercise - Understand what you're building
2. Try it yourself - Write code without looking at hints
3. Run the tests - Use cargo test to validate your solution
4. Peek at hints - If stuck, hints are in a separate section
5. Compare solutions - After solving, see alternative approaches
6. Do follow-ups - Extend the exercise with additional challenges

Prerequisites

• Basic programming experience (any language)
• Rust installed (rustup recommended)
• Familiarity with command line
• A code editor (VS Code, RustRover, etc.)

Philosophy

These exercises teach Rust by:

• Forcing natural usage: You'll reach for Rc<RefCell<T>> because you need it, not because you memorized when to use it
• Building intuition: Patterns emerge from solving real problems
• Embracing difficulty: Ownership errors teach better than explanations
• Celebrating progress: Each solved exercise is a real achievement

Ready to start? Head to Exercise 1: RPN Calculator!