Lately I've been filling my time in my cubicle doing Sudoku. It's way better than staring into blank space. And you know what, Sudoku is not THAT easy!
I find myself struggling to fill up the numbers vertically & horizontally. Most of the time I use the crude method of trial and error or "main belasah cuba nasib" which usually works like this: Fill random numbers in random box followed by immediately erasing said number upon realising that it wouldn't work after I've filled up another box with yet another seemingly random number (..phew). You can see a LOT of eraser marks on my Sudoku worksheet. Worse if it's on a newspaper. Kadang kadang sampai koyak.
There must be a better method than this. Filling up 9 horizontal & vertical lines randomly is hard, not to mention how much of a headache it is.
It was only today I realised that there's another little "rule" that I've missed.
Apparently, you have to fill the digits 1 to 9 in the nine 3 by 3 boxes as well.
Well... this certainly simplify things a bit.