Sudoku Tips - Daily Sudoku Puzzle

For the Sudoku Enthusiast, I have provide a new service on my site - Daily Online Sudoku Puzzle. You can now get your Free online puzzle everyday.

Welcome to my Sudoku community.

Have fun. :)

Sudoku Tips Series - Crazy Puzzle

Has anyone come across a crazy puzzle like this?





















The person who develops this is either a genius or math maniac.

I do like tough puzzle, it is a great challenge. But when one goes to the extreme, it will drives you go crazy.

Anyone wants to try? I look forward to your answer!

You may refer to my Guide for help! :)

Sudoku Tips Series – An Encounter with a Sudoku Fanatic

In the first series of this Sudoku Tips, I would like to share a real encounter with a Sudoku fanatic I met form my site.

I wrote this article History of Sudoku on my site which traces its origin. The history of Sudoku is said to trace back to 18th century. Very often, you will come across many sites that linked the development of Sudoku to Swiss mathematician Leonhard Euler. There are some sites even claimed that he invented Sudoku. Though it is not proven, it adds colours to the argument as to who actually invented Sudoku.

I received a strange email from a Sudoku fanatic, apparently a Japanese, who felt so strongly that the name Leonhard Euler should not even be mentioned in the history of Sudoku.

To protect his privacy, I won’t mention his name. But I gave him the credit for doing the thorough research.

Here’s what he wrote to me:

========================================

From: XXXXXXXX
To: <eric@sudoku-tips.com>
Sent: Thursday, September 29, 2005 1:01 PM
Subject: History of Sudoku (http://www.sudoku-tips.com/)

Most of what you wrote here is correct -- except the first paragraph:

"Sudoku is said to have 18th - century roots, but theorigins are unclear. It is believed the puzzle started from an 18th - century game invented by Swiss mathematician Leonhard Euler, which in turn was based on an ancient Chinese puzzle, Lo Shu."

The myth of the Euler connection is just laziness on the part of the press.

1) The origins of Sudoku ARE clear. Howard Garnes invented Number Place, Nikoli changed it and coined the name Sudoku. It origins as are concrete as can be, no more or less than the Rubik's cube.

2) Euler invented Graeco-Latin Squares (which are in no way related to or similar to Sudoku) using pre-exsiting knowledge of Latin Squares -- which pre-date his birth by several centuries.

A Latin Square is nothing more than an nxn array in which each digit from 1 to n appears once in each row and column. It is not a puzzle, nor are Graeco-Roman Squares.

This is a Latin Square:

1 2 3 4 5
2 3 4 5 1
3 4 5 1 2
4 5 1 2 3
5 1 2 3 4

As you can see, this is just to simple of a construction for to be attributed to ANYONE -- I'm sure both you and I independently "invente" it while scribbling in our notebooks in grade school.

The Graeco-Latin Square that Euler wrote about has two symbols in each cell, none of which are duplicated in any row or column. Each symbol pair appears exactly once:

1d 2b 3a 4c
3c 4a 1b 2d
4b 3d 2c 1a
2a 1c 4d 3b

As you can see, this has nothing to do with Sudoku, nothing to do with puzzles in general.

3) Neither Latin Squares nor Graeco-Latin Squares are"based on" Magic Squares, certainly not on the Lo Shu square. Euler wrote about "A new kind of magic square"-- refering to a way that Graeco-Roman squares could be used to generate magic squares. (Take the square above and replace the a, b, c and d with +0, +4, +8 and +12 and you'll get this:

13 6 3 12
11 4 5 14
8 15 10 1
2 9 16 7

.. see the Euler Archive:.http://www.eulerarchive.org/

(he ended with this strong statement…)
Euler has NOTHING to do with Sudoku, and though brilliant, didn't discover Latin Squares.

============================================

I followed the forum which he also participated in and I saw many heated posts written by him promoting his defensive theory against Euler.

A Sudoku fanatic? Sudoku Addict? I don’t know? But I admire his effort in doing the research and holding strong in his belief.

If you are keen to know the development of the Sudoku History, click on the link.

Just a day of History lesson on the subject of Sudoku! :)

My first Sudoku

Have you ever Sudoku?

The name Sudoku may sound like the hideous Sadako from the hit Japanese horror movie – The Ring. But Sudoku can be more terrifying than the female ghost who crawl out from the TV. It sucks up your brain cell and time.

Like many of you, I was hooked to Sudoku Puzzles.

My first encounter with Sudoku was way back to year 2000. A good friend of mine from Japan sends me a strange puzzle. In a box of 9 X 9 grids, there were few numbers listed randomly.

"Fill in the grid so that every row, every column, and every 3x3 box contains the digits 1 through 9" That's all she said.

“It's fun. It's challenging. It's addictive!” My friend warned me!

She told me that the puzzle is called Sudoku. No Sudoku Tips were offer to me. I was totally overwhelmed, I was addicted. Here’s the Sudoku Puzzle she sends me…..

To many Sudoku Fans, it is quite an easy puzzle; but at that time, it was a real challenge for a newbie like me. I am not ashamed to admit now that I did try to beg her for answer. She refused :)

It becomes a personal challenge that I must conquer this puzzle.

Over the next few days, I was totally stuck with the puzzle trying to solve the mystery, juggle in between my busy work schedule. It was a real frustrated experience, I admit :(

I was helpless without any guide or help…but I was excited. There were a few moments I feel like giving up, but I came back eventually.

I finally have it solved on the 4th day, after much trial and error. :)

When I look back now, it was a great experience. It is the satisfaction of achievement and the great experience of going through the lengthy rational thinking process that make me stays on with Sudoku.

Being a Sudoku Enthusiast for almost 5 years and the Author of The Sudoku Guide now, I have no regrets spending those times solving difficult puzzles. Over the years, playing Sudoku has helped me improve my thinking process, not just for solving puzzles, but in many aspects of work.

If you have not Sudoku yet, I encourage you to do so.

Before I sign off, last word of warning:-

Sudoku is exciting, it is fun, and it is addictive!

Don’t blame me for not warning you! :)

All the best, and have fun.