SUDOKU

Sudoku is a hobby that is believed to be invented in the 1970s and became popular in Japan in 1986, becoming known internationally in 2005 when many newspapers began to publish it on your hobbies section. The aim of sudoku is to fill a 9 × 9 grid divided into cells of 3 × 3 subgrids with the numbers from 1 to 9 based on some numbers and arranged in some of the cells. Although you could use colors, letters, figures, agrees to use numbers for clarity, what matters is that they are nine distinct elements that should not be repeated in the same row, column or subgrid. A sudoku is well posed if the solution is unique. Solving a sudoku always a Latin square, but the converse is not true in general since the sudoku provides the additional restriction that you can not repeat the same number in a region.

Rules and terminología

El sudoku is normally presented as a table of 9 × 9, consisting of 3 × 3 subtable called "regions" (it is also called "boxes" or "blocks").

Some cells already contain numbers, known as "givens" (or sometimes "tracks"). The aim is to fill the empty cells with a number in each, so that each column and row region contains the numbers 1-9 only once.

In addition, each issue of the solution appears only once in each of three "directions", hence the "the numbers must be single" evoking the name of the game.