Sudoku.Classic 2.0.2

Tutorial: The objective is to fill a 9x9 grid with digits so that each column, each row, and each of the nine 3x3 subgrids that compose the grid (also known as "boxes", "blocks", "regions", or "subsquares") contains all of the digits from 1 to 9. The puzzle setter provides a partially completed grid, which for a well-posed puzzle has a unique solution.

History: The modern Sudoku is believed to have been designed anonymously by Howard Garns, a retired architect and freelance puzzle constructor from Connersville, Indiana. It was first published in 1979 by Dell Magazines as Number Place, marking the earliest known examples of modern Sudoku. Garns's name consistently appeared in the list of contributors in issues of Dell Pencil Puzzles and Word Games that featured Number Place. However, it was absent from issues that did not include this puzzle. Unfortunately, Garns passed away in 1989 before witnessing the global popularity of his creation. It remains unclear if Garns was familiar with any of the French newspapers mentioned.

The puzzle was introduced in Japan by Nikoli in the paper Monthly Nikolist in April 1984 under the name Sūji wa dokushin ni kagiru (数字は独身に限る?), which translates to mean "the digits must be single" or "the digits are limited to one occurrence." The name was later shortened to Sudoku (数独) by Maki Kaji, who took the first kanji of compound words to create a more concise version. In Japan, "Sudoku" is a registered trademark and the puzzle is commonly known as Number Place (ナンバープレース) or more informally as Num(ber) Pla(ce) (ナンプレ). In 1986, Nikoli introduced two innovations: limiting the number of given digits to a maximum of 32 and ensuring symmetry in puzzles, distributing givens in rotationally symmetric cells. Currently, Sudoku is featured in various Japanese periodicals like the Asahi Shimbun.

The Times of London began including Sudoku in late 2004 following a successful introduction in a local US newspaper thanks to the efforts of Wayne Gould. Subsequently, it quickly became a regular feature in other newspapers. Gould developed a computer program to swiftly generate unique puzzles.