# Turner & Townsend backend technical assessment

This repository contains my solutions to the Turner & Townsend backend technical assessment. While the brief requested solving only one problem, I started with the "spiciest" Stack task for the first hour and then tackled the other two tasks in the second hour. I did come back the next day and spend some extra time improving the README documentation.

## Solutions

### [Stack Calculator](./stack/README.md)

**Complexity: Medium**

A stack-based programming language interpreter (Fifth) that supports arithmetic operations and stack manipulation commands. Features an interactive REPL with comprehensive error handling.

### [Roman Numerals Converter](./roman/README.md)

**Complexity: Medium**

Converts Roman numerals to Arabic numbers using additive logic. Includes flexible input handling with case-insensitive processing and automatic filtering of invalid characters.

### [Collatz Conjecture Calculator](./collatz/README.md)

**Complexity: Low**

Calculates the number of steps in the Collatz sequence (3n + 1 problem) with step-by-step visualization. Demonstrates mathematical algorithm implementation with interactive feedback.

## Architecture

All three solutions follow consistent design principles:

- Class-based structure for encapsulation and testability
- Interactive command-line interfaces with graceful error handling
- Comprehensive test suites with good coverage
- Modern Python features and best practices

## Quick Start

**Requirements:** Python 3.10+, pytest

```bash
# Install dependencies
pip install -r requirements.txt

# Run solutions
cd stack && python stack.py
cd roman && python roman.py
cd collatz && python collatz.py

# Run tests
pytest                    # All tests
pytest stack/            # Individual solution tests
```

Click the links above to view detailed documentation for each solution.