8-Puzzle Solver

Overview

This Python code implements the breadth-first search algorithm to solve the 8-puzzle problem. The goal is to rearrange a 3x3 grid of numbered tiles into a specific target state.

Getting Started

Prerequisites

• Python 3.x

Installation

1. Clone the repository:

   git clone https://github.com/collinblessing/8-puzzle-solver.git
   cd 8-puzzle-solver

2. Run the solver:

   python main.py

How it Works

The code defines a Node class representing a node in the search tree. Each node contains information about its state, parent node, and the action that led to its creation.

Functions

1. breadth_first_search(initial_state, goal_state)

   • Performs breadth-first search starting from the initial_state to reach the goal_state.
   • Uses a queue (frontier) to manage nodes to be explored and a set (explored) to track visited states.

2. get_successors(state)

   • Generates successor states of a given state by moving the empty tile in different directions.

3. reconstruct_path(node)

   • Traces back the path from the goal state to the initial state by following parent nodes.

4. get_inversion_count(state)

   • Calculates the inversion count of a given state, determining its solvability.

Coupling and Cohesion

The code exhibits good cohesion, with each function having a clear and specific role in solving the 8-puzzle problem. The Node class encapsulates relevant attributes, promoting cohesion within the codebase. The functions work cohesively to implement the breadth-first search algorithm.

Single Responsibility Principle

Each function adheres to the Single Responsibility Principle, with a clear and singular purpose. However, to enhance code readability and maintainability, it is suggested to extract the inversion count check into a separate function.

License

This project is licensed under the MIT License - see the LICENSE file for details.