It is the name of a popular pastime the many newspapers of the world. It consists of filling a 9 x 9 grid, subdivided into 3 x 3 grids with the digit numbers 1 through 9, preventing them from repeating in each section, in each column, and on each line. In addition, it should be ensured that two equal numbers are not continuous or faced. Game invented by the Swiss mathematician Leonhard Euler in the eighteenth century, which became popular as a pastime in the periods of the 80's. The Japanese word means number ( your ) only ( doku ) or single number.
