DelhiDekho

Rules

1. Each blank cell will have a single digit number  (1-9)
2. Each column (also nine lines from top to bottom), row (nine lines from left to right), and the 3x3 blocks bounded by bold line (nine blocks) will contain numbers from 1 through 9.

About Sudoku

Sudoku  is a logic-based number placement puzzle. The objective is to fill a 9×9 grid so that each column, each row, and each of the nine 3×3 boxes (also called blocks or regions) contains the digits from 1 to 9 only one time each. The puzzle setter provides a partially completed grid.

Completed Sudoku puzzles are usually a type of Latin square with an additional constraint on the contents of individual regions. Leonhard Euler is sometimes incorrectly cited as the source of the puzzle, based on his work with Latin squares.

The modern puzzle was invented by an American architect, Howard Garns, in 1979 and published by Dell Magazines under the name "Number Place". It became popular in Japan in 1986, after it was published by Nikoli and given the name Sudoku, meaning single number. It became an international hit in 2005