A good programming problem

There was a really good and tough problem in TCCC 2006 Algo Competition. None of around 600 participants could solve it in the given time.
You can try the problem in the practice arena.
And remember that your solution should not take more than 2 seconds for the worst case.

Technorati: contests, programming, TCCC, TopCoder

Made Indian ACM Ranklist

Was getting bored of writing php scripts for the cvitportal. So thought to make this site. It lists the top 100 Indians on the UVa acm site on the basis of number of problems solved. It is updated every hour unlike the one I told about here which has not been updated for months.
PS : PHP sucks.
PS1 : CGI Python rocks.

Technorati: ACM, programming, technical

IIIT ACM Toppers at UVa

The solvers of highest number of ACM problems on Uva site from IIIT Hyderabad are:-

Rank	Name	Problems Solved	Rank in India	Rank in World
1	Ankur Jaiswal	212	10	989
2	Manikandan Subramanian	118	23	2040
3	Visesh Uday Kumar	114	25	2115
4	Ankur Handa	102	29	2370
5	Bharat Joshi	92	34	2615

Note 1: Some of these guys are continuosly solving problems(one is solving right in front of me). So the above data may change by the time you read this.
Note 2: The ranks in India are not absolutely correct. They have been derived from the old data present on this site.
Note 3: I might have mistakenly left some IIITians name while browsing through the ranklist. Please let me no if someone is left out. Also those keeping logins different from their name are ignored.
Note 4: Kudos to Ankur Handa for being in Top 5 as he is in ECE and not CSE.

Technorati: iiit, ACM, technical, programming

Petr wins TCO 2006

		No Photo
Petr-1st	tomek-2nd	natori-3rd
fuwenjie-4th	misof-5th	andrewzta-6th
cyfra-7th	John Dethridge-8th

These are the eight topcoders who advanced to the finals in the sequence of their ranks in the finals. Petr won with a very comfortable margin as he was the only person to crack the hard one. For more on exact scores, visit this.

Technorati: TopCoder, programming

TopCoder TCO ... and the usual boring life

Currently 2006 TopCoder Open(TopCoder's Annual Algorithm Contest) is going on in Las Vegas ... Yes!! you heard it right, in LAS VEGAS. Las Vegas seems a unusual place to host such a contest but thats the Topcoder's Way. I love it. To make the TCO fun for the unlucky ones like me who could not qualify for the finals, TopCoder selected 4 official bloggers through its pick me contest to bring the action live to us. Now one would ask what action is there to watch? May be to you and many others it doesn't sounds exciting but I and the whole topcoder community loves to see/read how their favourites among those who qualified perform. Their ups and downs, the way a room leader falls down during the challenge contest and another one rises. Yes, TopCoder's contest have a lots of thrills. Every second you will be worrying if misof or antimatter or petr is viewing your code and has found a bug and you are going to be challenged. Even if you pass the challenge phase you can still be awarded 0(zero) if your code fails the system test. And as in any other contest, time limit is there, so not just pass the system test but pass it in the time limit. In other contests like ACM ICPC and majority of the online programming contests once you get "accepted" your solution is perfectly correct. But in TopCoder its not, first pass the challenges and then the system test , and you get just one opportunity. I mean that in other contests if your solution fails you can debug and resubmit, but not in TopCoder.... thats the thrill. For more on TopCoder's SRM details , visit my earlier post.
Ok.. so I was talking about the 4 official bloggers of TCO 2006. They all are doing fine and posting cool stuff - with pics of Las Vegas and all. To read their blogs, visit this page.
I would paste some of the cool photographs from Las Vegas here:-
The topcoder onsite arena:-


A close up with Omgrace, one of the official bloggers sitting there. Isn't the desk cool?( and isn't the lady hot :P )


The BIG monitors to watch whats happening during the contest for the use of onsite visitors.


The tall misof(left) with other topcoders:-

UVa ACM solvers would also recognize him(and many more topcoders) as he is an Experienced poster there. He is two time ACM ICPC winner or finalist I guess.(I don't remember exactly whether he was winner or just a finalist. By just a finalist I mean he was atleast in top three atleast once.)

The Usual Boring Life
Now about the usual boring life. Ther is little non-boringness here. Today I found out about G. Anand and "she" (I was 2 days late in knowing this) . My first reaction was a kind of laugh, and don't care. But as I read the whole blog from Sept. 2005 to current day I understood what it really was. I am sorry the way I laughed at G. Anand in his room at him. We all made a mockery of him. But its real. Their story is no less than a normal movie love story. As I read all the posts one by one, I felt as a movie is being played in front of my eyes.

The CVIT Portal
We have done absolutely no work after our presentation on Monday. First of all, we were not too happy at being given a portal to eat our summer time. But anyhow we started and thought to finsih it quickly and move on to our real project Content Based Image Retrieval(CBIR). But as everyone says Prof. Jawahar won't let us finish the portal quickly. We made almost half the portal before the presentation and then we were asked to change everything. New features etc. had to be added. Next time we meet may be we will have to redesign it once again. I wish I was one of the TopCoder Design/ Development Contestant who could do these kind of things so fast.

Technorati: TCO, TopCoder, programming, cvit, project

All about TopCoder

Next SRM is on 28th morning at 6:30 am IST. And yes it has lots of prizes as it is the 300th SRM. Do participate.
Nowadays I am addicted to TopCoder as I said in the last post. So what is TopCoder? Most of the IIITians here would already know about it as IIIT is primarily an IT institute. TopCoder conducts weekly programming contests in its own special arena(will write abt it later in the post) and you get a chance to compete with world's few of the finest coders.
Programming contests are conducted by other organisations as well, but they are not as thrilling and fun as TopCoder's is. ACM ICPC is one of the world's finest contest, but is conducted only once a year. Its true that there are hundreds of acm practice sites, but they don't have that thrill. They are just for practice.
TopCoder's weekly matches are termed SRMs - Single Round Matches. Let me till you a little about SRMs. Each SRM consist of three phases - Coding, Challenge and System Test. Actually only the first two of these are relevalant. In coding phase you will be given 3 problems : easy (300pts), medium(500pts) and hard(1000pts) and you have 1 hour and 15 minutes to code them all. Yes you heard me right , just 1 hr 15 mins!!! And there are in now way less challenging than ACM questions. The easy one is usually too trivial, medium one is alright, but the hard one is as good as an ACM Hard question. I am saying hard because half of the problems on acm.uva.es are too too too trivial. There are questions like subtracting two numbers, etc on ACM sites. Yes dudes, those of you thought ACM questions to be too tough or something , change your mind now. Have a look at this questions and see for yourself :-
272 : Tex Quotes : Just replacing quotes!!!
424 : Integer Inquiry : Adding integers using strings !!
458 : The Decoder : Just do ch=ch+7
488 : Triangle Wave : This you already did in your first sem
499 : What's the frequency : Simple Counting
There are hundreds of more dumb questions. And yes I do agree there are hundreds of pretty tough questions as well.
But whatever, doing 3 questions in 1 hour 15 mins at TopCoder requires some skills dude. But there are people here who do all three of them much before the time. The record is 15.50 minutes by Zis. All red coders here are ACM finalists or have been an ACM finalist during there time. Many of them are ACM coaches in some universities. So you have a chance to compete with the best coders and yes you can chat with them during the matches and on the forums.
Oh yes I forgot to tell you about TopCoder's rating system. All new members who have never competed in an SRM are called unrated and are white. Coders till rating of 800 are Grey. 800-1200 are Green, 1200-1500 Blue, 1500-2200 Yellow, 2200-3000 Red and above that are called target. I am currently Blue and its really easy to get a green or blue. Initially you compete in divison 2, which has extremely easy questions. (Don't frown when you see dumb questions when you participate for the first time .. coz you are in div2). Once you are Blue , that is you rating is above 1200, you start competing in divison 1. For actual rating formula, see this.
Ok this was all about coding phase. The competition does not ends here. Next comes the challenge phase - 15 mins . In this phase you can see others' codes and challenge their codes with a valid input if you think the code is wrong. You get 50pts for this and -20 [ EDIT : Its -25 actually ] if you have unsuccesfully challenged. I forgot to mention that , when you submit a solution during a SRM, then its not evaluated at that time. Its finally evaluated at the time of System Tests. That is when 100s of test cases are applied to your problem and you get zero if your code does not pass all system tests.
So does it sound good ?
If not then wait, there is more to topcoder. Maybe you don't like just programming but you like making softwares, etc. In that case you can compete weekly in design and development competitions. And I must say, they have a lot of prizes as these events are directly sponsored by IT companies. I can't tell you any more about design and development matches as I have never participated in any of these.
Then there are other events like Marathon Matches and Intel Multithreading Series.
And TopCoder also conducts an annual TCO which has a lots n lots of prizes. This year's finals will be starting in a few days in LAS VEGAS. (Yes, every year they choose cool locations for the finals).
And yes it was TopCoder only which conducts Google Code Jams.
And being a good scorer at TopCoder can enhance your resume. You can place following badges on your resume:-





Obviously, these are available in various sizes.
For more information about TopCoder, visit the FAQ section at Topcoder's website.

PS: Doesn't it look like I am advertising for TopCoder?
PS1 : Ohh! I forgot to write abt the arena. I will do it later :( Its too much for today.

Technorati: TopCoder, programming, ACM

Next post on topcoder

Nowadays I am totally addicted to Topcoder. Its not all about programming but there is a lot of fun in the forums as well. Well, this post was supposed to be all on Topcoder and why I am addicted to it. But due to lack of time ( I want to go to sleep early. Don't want to miss any more CVIT classes.) - so I was saying due to lack of time today I thought I won't do justice to it by finishing it too quickly. So I will be writing about Topcoder tomorrow. Keep waiting ... ( obviously only they who are interested :) ).
But LOL. This blog now seems useless. So let me post a screenshot of topcoder to make it up. It looks cool, isn't it ?

I know you would say why a screenshot. I donno myself. I am nowadays inclined towards putting pics on my blog, makes it look better :)

Technorati: TopCoder, programming

Google disqualified me

Ok... so i m back to blogger's world. Actually i never left it, i read almost all blogs on smr's blogroll. But i had stopped writing myself.
So lets come to the topic. Google disqualified from Google India Code Jam for no reason(not exactly).
Actually i used three logins during the contest. Now, I don't know how they found out that. But I m frustrated because i didn't actually cheat. My original Topcoder ID is(or rather was, its deactivated now:( ) was sandy007smarty. I participated using this ID and submitted 1 question for 230.95 points. Then after some 3 hours or so , i used one of my friends ID to sign into the contest. But this time i just saw the questions of this set and didn't submit any code. Again after 1 hour or so i opened another ID and again didn't submit anything.
Now, google says(they mailed me) that its against their rule to use more than 1 login. And, therefore I m disqualified.

Now how did they found out that i was the one who used all 3 ids? I guess they extracted out my internal LAN IP because i opened all three logins from the same PC. But if they are smart enough to extract my internal IP, then don't they have the common sense to see that i didn't submit anything from other two IDs? Also the other two IDs I opened 3hrs after i submitted problems from my original id. So there is no case of cheating. Also what if some other person had participated from the same machine(its a lab PC, any1 can use) then we would both have been disqualified? This is not fair. And this is the case when they took almost 16 hrs to eliminate all cheaters and still couldn't eliminate all cheaters(there are ppl with score >249 out of 250) and falsely eliminated me.

I m not the only case. There is a guy from Dhaka who has solved around 1500 questions of ACM and is a acm tutor for his college, and google has disqalified him. See this link.Do u think a guy who solved 1500 ACM questions needs to cheat to get through the qualification round. Let me tell u that the 250 point question was really really easy(i did it in 7 mins). And the cut-off was 91, which means a guy who takes around 50-55 mins to solve such a easy question has also qualified.
Whatever, i m disqlaified and would take care that i don't do such stupid things next time.
PS: I mailed them and told them to check my past performance in Topcoder's SRMs and see that I could easily solve that question without any cheating. But their reply was negative.

Technorati: google, TopCoder, programming, contests, personal, life