|
|
Each Puzzle has one and only one solution that can be solved without guessing. Enter numbers 1 to 9 into the blank spaces. Each column and each row must contain one of each digit. So must each of the nine 3x3 squares.
HISTORY OF SUDOKU
Le Siècle, a French daily, produced a 9x9 grid with 3x3 sub-squares as early as 1892, but used double-digit numbers rather than the familiar 1-9. In 1895, another French daily, La France, created a puzzle that used the numbers 1-9 but did not mark the 3x3 sub-squares. These weekly puzzles were a feature of newspaper titles including L'Echo de Paris for about a decade but disappeared about the time of the First World War.
The modern Sudoku was designed anonymously by Howard Garns, a 74-year-old retired architect and freelance puzzle constructor, and first published in 1979. Garns added a third dimension to the traditional Roman practice of Latin Squares and presented the creation as a puzzle, providing a partially-completed grid and requiring the solver to fill in the rest. The puzzle was first published in New York by the specialist puzzle publisher Dell Magazines in its magazine Dell Pencil Puzzles and Word Games, under the title Number Place.
The puzzle was introduced in Japan by Nikoli in the paper Monthly Nikolist in April 1984 as Suuji wa dokushin ni kagiru, which can be translated as "the numbers must be single" or "the numbers must occur only once." The puzzle was named by Maki Kaji, the president of Nikoli. At a later date, the name was abbreviated to Sudoku, taking only the first kanji of compound words to form a shorter version. In 1986, Nikoli introduced two innovations: the number of givens restricted to no more than 32 and puzzles became "symmetrical" (meaning the givens were distributed in rotationally symmetric cells). It is now published in mainstream Japanese periodicals, such as the Asahi Shimbun.
This article Uses material from the Wikipedia article "Sudoku" and is licensed under the GNU Free Documentation License, which means that you can copy and modify it as long as the entire work (including additions) remains under this license.
|
|
|
|
