Sudoku puzzle, is a widely popular intellectual game in recent years, was invented in Swiss in 18th century. The name Sudoku actually derives from Japanese that means “number place. In Japan Sudoku became immensely popular since 1984. In 2004, The Times in London published its first daily Sudoku, reintroducing the Sudoku puzzle to Western culture. Sudoku quickly spread to newspapers all over the world, delighting users every single day.
While Sudoku puzzles can be rather challenging, the rules and general game play are pretty simple and straightforward.
Sudoku is played on a grid of 9 by 9 cells in which some of the cells are filled with numbers. The goal of the game is to fill the empty cells such that the numbers from 1 to 9 appear only once in each row, column and block (a block is a 3 by 3 grid).
A valid Sudoku has a one posible solution which can be found using an array of solving techniques without the need to guess. The difficulty of a Sudoku is determined by the level of the solving techniques required to solve it.
There are many Sudoku solving techniques developed. Some of them are listed below: