sudoku
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Sudoku
Sudoku ( sdoku), also known as Number Place or Nanpure, is a logic-based placement puzzle. The aim of the puzzle is to enter a numerical digit from 1 through 9 in each cell of a 99 grid made up of 33 subgrids (called "regions"), starting with various digits given in some cells (the "givens"); each row, column, and region must contain only one instance of each numeral. Completing the puzzle requires patience and logical ability.

Euler is frequently cited as the source of the puzzle, but examples of Latin Squares were engraved in ancient architecture as numerological talismans. Euler made no changes to their rules. Arabic numerologists had already compiled an exhaustive list of order 3 through order 9 Greco-Latin Squares in the Jabirean Corpus by 990 AD.

The modern puzzle Sudoku was invented in Indianapolis in 1979 by Howard Garns. Garns contributed his puzzles to Dell Magazines, which published them under the moniker "Number Place". Interest in Sudoku surged from a revival in Japan in 1986, when puzzle publisher Nikoli discovered the game in older Dell publications, and republished the format leading to widespread international popularity in 2005.

Introduction


The name "Sudoku" is the Japanese abbreviation of a longer phrase, "Suuji wa dokushin ni kagiru" (֤϶ޤ), meaning "the digits must remain single". It is a trademark of puzzle publisher Nikoli Co. Ltd. in Japan. In Japanese, the word is pronounced [sɯːdokɯː]; in English, it is usually spoken with an Anglicised pronunciation, [səˈdəʊkuː] (BrE) [səˈdoʊkuː] (AmE) or ['suːdəʊku] (BrE) ['suːdoʊku] (AmE) (See IPA (International Phonetic Alphabet) or IPA chart for English for notation usage.) Other Japanese publishers refer to the puzzle as Number Place, the original U.S. title, or as "Nampure" for short. Some non-Japanese publishers spell the title as "Su Doku".

The numerals in Sudoku puzzles are used for convenience; arithmetic relationships between numerals are irrelevant. Any set of distinct symbols will do; letters, shapes, or colours may be used without altering the rules. In fact, ESPN published Sudoku puzzles substituting the positions on a baseball field for the numbers 1-9. Dell Magazines, the puzzle's originator, has been using numerals for Number Place in its magazines since they first published it in 1979.

The attraction of the puzzle is that the rules are simple, yet the line of reasoning required to solve the puzzle may be complex. The level of difficulty can be selected to suit the audience. The puzzles are often available free from published sources and may be custom-made using software.

Play on-line


here is a simple Sudoku.

Yasminoku

Yasminoku is an open source "Sudoku" alike game totally written in DHTML (JavaScript, CSS and HTML) that uses mouse. Includes Sudoku Solver. This cross-platform and cross-browser game was tested under BeOS, Linux, *BSD, Windows and others.Recommended!

The Project Admins is Joan Alba Maldonado, here is his homepage and Yasminoku page, you can download the Yasminoku project here.

Play Yasminoku on-line:  English  |  Chinese

How to solve?


English version:
1. Getting started, 2. Making progress, 3. Reaching out, 4. Raising numbers.

Chinese version:
Getting started Making progress Reaching out Raising numbers

Color Book: How to solve Every Sudoku Puzzle?

you can download the color book here: | Vol 1 | Vol 2

Sudoku Helper


The Sudoku Helper is created by J.P. Grossman, it's very powerful, you can load a puzzle from millions of websites and can have a step-by-step solve and quick solve. Recommended! There is also a strategies instruction.

Sudoku Solver by Logic


the page is powered by sudokusolver.co.uk, the solver is also very powerful, it can record and output the step-by-step notes created by the solver in both English and Chinese. Recommended!

English version here, if you prefer the clean solver (without uncalled-for text), click here. There is a Chinese version and Sudoku Coding Challenge page.

Scanraid Sudoku Solver

Methods


a multilingual Solve Methods Page

Strategies


Sudoku Game Downloads


The download page contains several classic sudoku game. Enjoy it! Have fun!

Links


Sudoku.com  http://www.sudoku.com/
Sudoku by Pappocom -- the home site for everything Sudoku, including the Sudoku computer program, and home of the Sudoku Players forums.

Scanraid Sudoku Solver  http://www.scanraid.com/Sudoku.htm
Sudoku Solver by Scanraid Ltd. Shows the logic behind solving Sudoku square by square.

Sudoku Solver by logic  http://www.sudokusolver.co.uk/
A Sudoku Solver that tries to solve Sudokus by logic only

Wikipedia: Sudoku  http://en.wikipedia.org/wiki/Sudoku
Sudoku From Wikipedia, the free encyclopedia

Web Sudoku  http://www.websudoku.com/
Play Sudoku online from easy to evil. Web Sudoku also supplies Sudoku puzzles for newspapers, magazines, Sudoku books and websites.

Daily SuDoku  http://www.dailysudoku.com/sudoku/index.shtml
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Sudoku.org.uk  http://www.sudoku.org.uk/
Sudoku tips, strategies, information and help from Michael Mepham for London Daily Telegraph and Los Angeles Times solvers.

Sudoku.com.au  http://sudoku.com.au/
Free Sudoku. 4 new sudoku per day. Easy Sudoku for Wed

Sudoku Puzzles  http://www.sudoku-puzzles.net/
Here you find lots of free Sudoku puzzles. The puzzles can be played online, printed out and even exported as PDF-File.

JavaScript Sudoku Solver  http://www.ccs.neu.edu/home/ramsdell/tools/sudoku.html
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you must get permission from the respective author before reproduction