0x05-nqueens

0x05. N Queens ♛

📖 Project Overview

The N Queens problem is a classic algorithmic challenge of placing N non-attacking queens on an N×N chessboard. This project involves using backtracking to explore and print all possible solutions, helping you strengthen your understanding of recursion and algorithmic optimization.

🎯 Learning Objectives

• ♻️ Backtracking: Use backtracking to explore solution paths and revert when necessary.
• 🔄 Recursion: Leverage recursion to handle repeated function calls and explore solution spaces.
• 📋 List Manipulations: Store and track the position of queens on the chessboard.
• 🖥️ Command Line Arguments: Manage input arguments using Python’s sys module.

🛠️ Technologies Used

• Python 3.4.3 on Ubuntu 20.04 LTS
• PEP 8 (v1.7.*) for code style and formatting

📋 Requirements

• Files must run on Ubuntu 20.04 LTS using python3 (version 3.4.3).
• Files should start with #!/usr/bin/python3.
• Code should conform to PEP 8 standards.
• Ensure all files are executable and contain complete documentation.

🚀 Installation

1. Clone the repository:

   git clone https://github.com/Alogyn/alx-interview
   cd alx-interview/0x05-nqueens

2. Run the program:

   ./0-nqueens.py N

   Replace N with the desired board size (an integer ≥ 4).

📝 Task Breakdown

N Queens Challenge ♛:

• Goal: Write a program to solve the N queens puzzle, ensuring each queen is placed such that no two queens attack each other.

• Program Usage:

  nqueens N

• Error Handling:

  • If the number of arguments is incorrect, print: Usage: nqueens N.
  • If N is not an integer, print: N must be a number.
  • If N < 4, print: N must be at least 4.

• Output: Each solution is printed in a list format, with each list element representing the row and column position of a queen.

Example

$ ./0-nqueens.py 4
[[0, 1], [1, 3], [2, 0], [3, 2]]
[[0, 2], [1, 0], [2, 3], [3, 1]]

🧠 Key Concepts

• Backtracking Algorithms: Solve problems by exploring all solutions and discarding those that fail to meet requirements.
• Recursion: Efficiently explore solution paths with recursive calls.
• Command-Line Input: Handle user input through the command line using Python’s sys module.

⚖️ License

This project is licensed under the ALX Software Engineering Program. © 2024 ALX. All rights reserved.