What is SUDOKU ?

Sudoku, Su Doku, or Number Place, depending on the publisher, are all names for a unique type of puzzle. A sort of crossword puzzle for numbers, sudoku originated in the United States as Number Place. However, it was not until a Japanese company, Nikoli, published the first sudoku puzzle in Japan that this type of puzzle became popular.

Since then, sudoku puzzles have gained international recognition almost 20 years after they became popular in Japan. These puzzles are now published in newspapers around the world and are rapidly becoming every bit as much a fixture of a major paper as a crossword.

The rules for these puzzles are simple, but the puzzles can be very difficult to complete. The puzzles usually are placed on a 9x9 grid, divided into 3x3 square regions. The goal is to complete the blank squares so that each row, column, and square region contains each of the numbers 1-9 exactly once.