Sudoku Solver & Generator (Java)

A compact Java Swing project demonstrating:

• Backtracking recursion with basic optimization
• Sudoku puzzle generation with unique-solution checking
• A Swing GUI to input, validate, solve and generate puzzles

What’s included

• src/sudoku/ — all Java source code (Board, Solver, Generator, GUI)
• samples/ — sample puzzles (easy/medium/hard)
• tests/SolveTest.java — quick console test
• build.sh / run.sh — optional convenience scripts

Features

• Solve any 9×9 Sudoku (backtracking with heuristic)
• Generate puzzles (difficulty: easy/medium/hard)
• GUI: enter puzzle, Solve, Clear, Generate, Check validity
• Solver validates inputs and shows "No solution" when appropriate

How to build & run (plain javac)

# from project root
javac -d out src/sudoku/*.java
java -cp out sudoku.Main