Month completed: February 2009

If at first you don’t succeed; try, try, try again

Or in the case of this goal:

If at first you don’t succeed, leave it for a year, then try again just once more

I really like Sudoku puzzles. They are based on a simple concept of finding the right box for the right number, they require systematic logic to solve, and there seem to be limitless number of puzzles available.

Most of the time a puzzle is classified as easy, medium, hard or difficult. But I had heard of a Sukodu puzzle that was considered the world’s hardest.

AI Escargot.

Here is a description of it from it’s creator, Arto Inkala, a Finnish mathematician -

“AI Escargot demands those tackling it to consider eight casual relationships simultaneously while the most complicated variants attempted by the general public only require people to think of one or two combinations at any one time.” Read more.

So of course, completing this Sudoku, and thus saying I had officially completed the world’s hardest Sudoku, offered immense appeal.

Early in 2008 I tried to complete it. I used my usual system of solving a Sudoku puzzle, but despite close to 40 attempts, I could not crack it. I was extremely close on one occasion, completing the puzzle only to realize that one row had a duplicate number in it.

After 40 attempts, I thought I had been though every possibility and was deriving nothing but annoyance from the puzzle.

So I stopped trying. I put it away. To try again another day.

Until last weekend, when I decided to have another try.

As I mentioned at the start of this post, to my utter shock, on my first attempt, I cracked the puzzle. As you can imagine, my jaw almost hit the ground.

What I take from this goal is a great sense of accomplishment, but more so I take away the lesson that sometimes when in a situation that looks to have no answer, the best thing is to just leave it alone. Forget about it. Go do something else.

And when you re-visit it, with fresh eyes, the answer might just be staring you in the face.

A year long wait might be a bit over the top though!

If you want to see my completed AI Escargot, click here. But don’t click it until you have had a go.

UPDATE – One of the comments below also contains a correct answer. Interestingly it is different to mine. Please avoid the comments if you want to work it out for yourself.