Sudoku

Sudoku is a fairly new addition to the Dominion Post newspaper and is fast becoming an obsession around here. Sudoku is a placement puzzle and is also known as Number Place in US. The basic concept is very simple to understand: A grid containing 9 rows and 9 columns (subdivided into three groups each) is to be filled with numbers. Each row and each column must contain all digits from 1 to 9 (without repetition). The rows and columns are then grouped into threes giving nine smaller grids containing 3 rows and 3 columns. These smaller grids must also contain all 9 digits. Some of the digits are already filled out in the grid and the rest needs to be filled in.

Sound simple? Well, it's not as simple as it sounds. The newspaper has been carrying three different levels of Sudoku and I have only been able to complete the first two levels. The "tough" one still eludes me. But, not for long!