Sudoku Plus ! A Sudoku software for nokia mobiles

This is the climax of a fascinating chapter of my life- sudoku. Yeah those who have been here before know about me and Sudoku :) This effort is to tell the world that all the work I put in, just out of fascination and passion, has come to an exciting finish.

I joined Webonise Software Solutions last month as mobile application developer. Here with all the support needed to turn my work into a finished product, we managed to develop an amazing piece of software that not only works well but it looks awesome too. Have a look at Sudoku Plus !

As you can see, Nayan Deshmukh, co- founder at Webonise Lab designed an amazing user experience for the Sudoku Plus.

This month we launched sudoku plus on Ovi store for all nokia touch phones covering S60 V5 and now S60 V3 i.e. all the e series devices. So far we have received an amazing response on the ovi store averging almost 2000 downloads per day. With E series support added, even this rate is expected to increase.

You can take a detailed look at Sudoku Plus on out product page or at Nokia Ovi store.

There are a few things that can still be added to this little thing. But everything has its time. Something equally interesting is going on at weboniselab right now, and if all goes well you may see another elated post here. :)

Web developement using gwt and google app engine

Getting into new environment of web development. Now that I have learned many languages and done some good bit of coding on desktop its really a high time for me to start with this web dev thingy.

Of course I wasn't a total noob in web arena.(I knew html :D ) I started poking around here and there on web ,with some knowledgeable friends and zeroed in on Google app engine along with Google Web Toolkit for my first web application.

For starters GAE is a platform that can be used to deploy your application on Google infrastructure. Google takes care of everything for your application, no servers to manage ,no scaling problem, nothing. It can be programmed in either jvm based language --java,jsp, ruby or using python. It can be used for free for moderate use (5 million page views) and pay according to resources used thereafter. It is just as cool as it gets.

As for GWT , its one of those great things that Google has done. Its well known applications include newer version of AdSense and Google Waves. This technology is especially designed for java developers and I bet they love it. Major advantage is that you are not required to be expert in browser quirks and no separate testing is required for each browser (don't need to worry about IE6 compatibility :D ). And you have all the advantages that java coding offers and disadvantages too (for some people).

Now the combination Gwt and Gae is great. You can develop and deploy great,scalable applications for free at the start. You get a plugin for eclipse- Google plugin for eclipse, which makes it very easy to develop, manage and deploy any such project.
I have started working on it, and as I have the library ready for use at the back-end, my first web application in going to be an Ajax based, sudoku puzzle generator and solver. Currently using free domain from google - My sudoku app.

Sudoku

Blogging after a long time, much due to lack of interest and a bit of time factor as these six months were the most happening months of the engineering life. Much has happened that is worth noticeable but that would merit a separate post.

Today my interest is SuDoKu - A long time passion for me.I have been developing a cpp code that would generate and solve a variety of types of SuDoKu problems in a fast and efficient way.I succeeded in developing a code that would satisfy my requirement a long time ago.i.e 3-4 months back. But now I am more interested in improving the code and its response time in case of solvers.

Interestingly, during any operation in SuDoKu one needs to check the validity of the number to be input at the given place in the 9X9 grid. This check involves checking 9 blocks for row,column and 3X3 block respectively. This would require 27 iterations for each check! This was the major time consuming part of the code. I started using different methods for decreasing the response time.

As I was using guessing along with logical analysis, solution time was never going to be constant.
So in order to obtain mean solution time, I devised a function to run the code on a standard problem 10,000 times and then take the mean. As for the need for reduction of the iterations, I used indexing of the positions in the SuDoKu grid. When any number is entered at any position it would trigger a flag index that contains information for a particular number at a particular position. This brought the number of iterations from 27 to just 3! But it cost 3 times as much memory. But from the context of overall memory requirement of program, it was drop in the ocean.

So I started chasing the fastest solution time with (+/-)5% error. Now I am proud to have succeeded in developing a code that solves the Hardest SuDoKu Puzzle. Now for an average sudoku puzzle it gives mean solution time of 9 millisecond on a P4-2.88 G Hz machine. Other factors other than that of processor speed may affect the time but that would be within 5% error range. So I feel pretty satisfied with my achievement.

You can get the source code here.

Most of the goals about SuDoKu other than cross platform compatibility(much due to lack of interest in learning new graphics library) have been fulfilled. So now it is full-stop to SuDoKu and I am all geared up for a new challenge. After all, only goal is to Excel!