Sudoku

Sudoku which has taken the world by storm has become one of my latest infatuation. Sudoku is a simple game of logic, in which the objective is to complete the grid such that every row, every column, and every 3x3 block contains the digits from 1 to 9. Simple as it sounds, but comes in variety of difficulty levels and each puzzle is enticing in its own way and has something to offer which simply makes it an addiction!

Here's an interesting article about history of Sudoku:

The concept of Sudoku (Japanese: 数独, sūdoku) seems to begin with the Swiss mathematician Leonhard Euler who in 1783 invented Latin Squares - NxN grids which have all numbers from 1 to N appearing exactly once in each row and column. Because Euler used Greek letters, these grids were often called “Graeco-Latin Squares”. Sudoku puzzles as we know them were first published in the late 1970’s in Math Puzzles and Logic Problems magazine by Dell Magazines. The name given by Dell to these puzzles was Number Place, as they are still called by this company until today. Dell took Euler’s Latin Square concept and applied it to a 9x9 grid with the addition of nine 3x3 sub-grids, or boxes, each containing all numbers from 1 to 9.

So, the Sudoku concept was not invented in Japan as many people may believe, but the name Sudoku was. In 1984 Nikoli, Japan’s leading puzzle creating company, discovered Dell’s Number Place and decided to present them to their Japanese puzzle fans. The puzzles, which were first named Suuji Wa Dokushin Ni Kagiru, ("the numbers must be single" or "the numbers must occur only once") quickly became popular. In 1986, after some important improvements were added, mainly by making symmetrical patterns and reducing the number of given clues, Sudoku became one of the best selling puzzles in Japan. Realizing that the only problem with the Sudoku puzzles was their long name, Kaji Maki, the president of Nikoli abbreviated it to Sudoku - (Su = number, digit; Doku = single, unmarried). Today there are more than 600,000 copies of Sudoku magazines published solely in Japan every month.

At the end of 2004 Wayne Gould, a retired Hong Kong judge as well as a puzzle fan and a computer programmer, visited London trying to convince the editors of The Times to publish Sudoku puzzles. Gould, that had written a computer program which generates Sudoku puzzles of different difficulty levels, demanded no money for the puzzles. The Times decided to give it a try and on November 12, 2004 launched their first Sudoku puzzle. The publishing of Sudoku in the London Times was just the beginning of an enormous phenomenon which swiftly spread all over Britain and its affiliate countries of Australia and New Zealand. Three days later The Daily Mail began publishing Sudoku puzzles titled as "Codenumber". The Daily Telegraph of Sydney followed on 20 May 2005. By the end of May 2005 the puzzle was regularly published in many national newspapers in the UK, including The Daily Telegraph, The Independent, The Guardian, The Sun and The Daily Mirror. <>But that was not it. In July 2005 Channel 4 included a daily Sudoku game in their Teletext service and Sky One launched the world's largest Sudoku puzzle – a 275 foot (84 meter) square puzzle, carved in the side of a hill in Chipping Sodbury, near Bristol. The BBC Radio 4's Today began reading numbers aloud in the first Sudoku radio version. Famous British celebrities as Big Brother's Jade Goody and Carol Vorderman, that her book How to do Sudoku is the best-selling book in the country, have testified to its benefits as a mental workout. Even the Teachers magazine which is backed by the government recommended Sudoku as brain exercise in classrooms and suggestions have been made that Sudoku solving is capable of slowing the progression of brain disorder conditions such as Alzheimer's.In April 2005 Sudoku completed a full circle and arrived back to Manhattan as a regular feature in the New York Post. On Monday, July 11, the Sudoku craze spread to other parts of the USA when both The Daily News and USA Today launched Sudoku puzzles on the same day. In both cases the Sudoku puzzles were instead of traditional crosswords and bridge columns.

Today there are Sudoku clubs, chat rooms, strategy books, videos, mobile phone games, card games, competitions and even a Sudoku game show. Sudoku has also sprung up in newspapers all over the world and is commonly described in the world media as "the Rubik's cube of the 21st century" and as the "fastest growing puzzle in the world".

For some Sudoku strategies, click here.

Arpit.