Sudoku Game

What is Sudoku?

Sudoku is a classic logical reasoning number game that originated in Switzerland in the 18th century, later promoted in Japan and popular worldwide. The goal of the game is to fill a 9×9 grid with numbers 1-9 so that each row, column, and each 3×3 box contains all numbers 1-9 without repetition.

Game Features

• Multiple Sizes: Supports 4×4, 6×6, 9×9, 12×12, 16×16 and other sizes, suitable for players of different levels
• Three Difficulties: Easy, medium, and hard three difficulty levels, from beginner to challenge
• Smart Hints: Provides solving hints to help players learn Sudoku techniques and reasoning methods
• Real-time Validation: Supports automatic validation and manual validation, detect errors in time
• Undo/Redo: Supports undo and redo operations, saves up to 50 steps of history
• Candidate Marking: Supports candidate number marking mode for easy recording of possible numbers
• Auto Save: Game progress is automatically saved locally, no loss on page refresh
• Timer Statistics: Records completion time, moves, hint count, and error count
• Best Scores: Saves best completion time for each difficulty and size
• Responsive Design: Perfectly adapted for mobile and desktop, supports touch and keyboard operations

Game Rules

• Fill in numbers in the grid so that each row, column, and box contains all numbers from 1 to N (N is the grid size)
• Each number can only appear once in the same row, same column, and same box
• Numbers already given in the puzzle (gray background) cannot be modified
• Numbers entered by players (blue) can be modified or deleted
• When all cells are filled with correct numbers and there are no conflicts, the game is complete

Sudoku Techniques

• Naked Single: A cell has only one possible number, fill it directly
• Hidden Single: A number has only one possible position in a row, column, or box
• Elimination: Analyze constraints of rows, columns, and boxes to eliminate impossible numbers
• Candidate Marking: Mark all possible numbers in uncertain cells, gradually narrow down the range
• Box Elimination: Use number constraints within boxes to eliminate possibilities in other boxes
• Pairs/Triples: When two or three cells can only contain the same few numbers, you can eliminate these numbers from other positions

Operation Instructions

• Select Cell: Click a cell or use arrow keys to move selection
• Enter Number: Use number keys 1-9 or click the number panel to input
• Delete Number: Press Delete or Backspace key, or click the “Clear” button
• Toggle Mode: Switch between “Number” and “Candidate” modes
• Get Hint: Click the “Hint” button to get the next step suggestion
• Validate Answer: Click the “Validate” button to check if the current solution is correct
• Undo/Redo: Use “Undo” and “Redo” buttons to revert or restore operations
• Auto Solve: Click the “Solve” button to automatically complete the entire Sudoku

Sudoku History

The origin of Sudoku can be traced back to the concept of “Latin Squares” by Swiss mathematician Leonhard Euler in the 18th century. The prototype of modern Sudoku appeared in 1979, designed by American architect Howard Garns, originally named “Number Place”. In 1984, Japanese magazine “Nikoli” introduced it to Japan and named it “Sudoku” (すうどく), meaning “single number”. Sudoku quickly became popular in Japan and swept the world around 2005, becoming one of the most popular logical reasoning games.

Benefits of Sudoku

• Exercise Logical Thinking: Train logical thinking skills through reasoning and elimination
• Improve Concentration: Requires careful observation and analysis, helps improve concentration
• Relieve Stress: As a leisure activity, helps relax the mind
• Prevent Cognitive Decline: Regular logical reasoning activities help keep the brain active
• Cultivate Patience: Solving complex Sudoku requires patience and perseverance