| Author | Message | ||
     Anand_n Hero Username: Anand_n Post Number: 10017 Registered: 02-2008 Posted From: 70.120.91.149 Rating: N/A |
My son watches the physics lectures on academic earth  Will ask him to check out the Comp Sci stuff when he starts the course next year Thanks for the resource links aa chal ke tujhe main leke chalu ik aise gagan ke tale jahan gam bhi na ho, aansoo bhi na ho,bas pyaar hi pyaar pale | ||
| Entikaburlu Junior Artist Username: Entikaburlu Post Number: 735 Registered: 07-2011 Posted From: 67.247.83.224 Rating: N/A |
Thanks!! ".. be fearful when others are greedy and be greedy only when others are fearful." - Warren Buffett | ||
| Entikaburlu Junior Artist Username: Entikaburlu Post Number: 731 Registered: 07-2011 Posted From: 67.247.83.224 Rating: N/A |
another trivia: Prof SN Maheswari - the IITD CS Prof who taught Data Structures and Algo to my class - has a standing deal. Either you attend every single class, do every single homework and quiz, and write two minors and one major test to get an A. Or, he will pick a problem of his choice from Don Knuth's Vol #1 only (that's enough for us the poor souls) and solve it. Apparently some kids got the A using the second route. Though there wasn't one on the campus when I studied. ".. be fearful when others are greedy and be greedy only when others are fearful." - Warren Buffett | ||
| Entikaburlu Junior Artist Username: Entikaburlu Post Number: 730 Registered: 07-2011 Posted From: 67.247.83.224 Rating: N/A |
here is trivia about Don Knuth's box set. If anyone can read all three volumes, just send an email to Bill Gates, Microsoft will hire you. It is a standing offer Bill Gates made when he was the CEO, and I believe it is still honored today. ".. be fearful when others are greedy and be greedy only when others are fearful." - Warren Buffett | ||
| Immotional_hatyachar Junior Artist Username: Immotional_hatyachar Post Number: 234 Registered: 05-2011 Posted From: 204.14.239.210 Rating: N/A |
Thanks Bro | ||
| Entikaburlu Junior Artist Username: Entikaburlu Post Number: 729 Registered: 07-2011 Posted From: 67.247.83.224 Rating: N/A |
here: http://www.interviewstreet.com/recruit/challenges/dashboard/ ".. be fearful when others are greedy and be greedy only when others are fearful." - Warren Buffett | ||
| Congfan Junior Artist Username: Congfan Post Number: 322 Registered: 06-2008 Posted From: 99.94.190.148 Rating: N/A |
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| Entikaburlu Junior Artist Username: Entikaburlu Post Number: 728 Registered: 07-2011 Posted From: 67.247.83.224 Rating: N/A |
I do not know how to reply to multiple posts at the same time, so let do a half-assed attempt here: Anand_n: Thank you! Vij Warrior: Bro, thanks - mana vijiwada!! PplSuck: Thanks!! SriSri01: Thank you, Sir! ".. be fearful when others are greedy and be greedy only when others are fearful." - Warren Buffett | ||
| Immotional_hatyachar Junior Artist Username: Immotional_hatyachar Post Number: 233 Registered: 05-2011 Posted From: 204.14.239.210 Rating: N/A |
where are these problems? | ||
| Srisri001 Junior Artist Username: Srisri001 Post Number: 240 Registered: 03-2008 Posted From: 71.244.102.123 Rating: N/A |
Entikaburlu: As always you rock! You are a great inspiration to many DBers! | ||
| Pplsuck Side Hero Username: Pplsuck Post Number: 2899 Registered: 07-2008 Posted From: 184.145.53.153 Rating: |
Great man....congrats....nice listening to someone who knows their stuff.......like your simplicity and honesty.....and you have a great attitude.......keep rocking.....good luck..... | ||
| Vjawarrior Junior Artist Username: Vjawarrior Post Number: 913 Registered: 02-2011 Posted From: 70.104.91.41 Rating: N/A |
awesome Enti kaburs Bro....Congrats.. | ||
| Anand_n Hero Username: Anand_n Post Number: 10013 Registered: 02-2008 Posted From: 70.120.91.149 Rating: N/A |
Congratulations - its nice to see the passion with which you are working these Goodluck with the rest aa chal ke tujhe main leke chalu ik aise gagan ke tale jahan gam bhi na ho, aansoo bhi na ho,bas pyaar hi pyaar pale | ||
| Entikaburlu Junior Artist Username: Entikaburlu Post Number: 726 Registered: 07-2011 Posted From: 67.247.83.224 Rating: |
wanted to share my experience so far- first and second problems were quite easy, I was spot on. that made me quite arrogant, I guess. I submitted the #3 rather quickly, one of the test cases was failing with CPU limit exceeded. So, I created a test case with 10^6 entries on an infinite grid - the problem is to find the point that is cummulatively least expensive. for e.g. if you have 10 million friends, they all want to attend a get-together and you have to pay for everybody' travel, what location would you choose, so that your overall bill is mimimum. so this is called Facility Problem, Min-Sum problem etc. my first solution took 18 minutes!! that made me sober up. first optimization was a total rewrite, which came to 2 mins. Still it was above CPU limit. Then another 3 days of continuous thinking - this time it was about 40 sec. I was about to give up. this morning another brain wave - another rewrite - under 2 seconds. I was so flabbergasted. a million points - you find the min-sum in less than 2 sec. The power of the algorithms is so enormous, it is just unbelievable. The algorithms I considered and tried are these: Dijkstra's famous algorithm: http://en.wikipedia.org/wiki/Dijkstra%27s_algorithm Did not use this, as the problem at hand is euclidian(x-y coordinates), where is Dijkstra's algo is for general including obstructions. see the cool animation in the above page. The brute force algo using the euclidian variant of dijkstra took 18 mins. The next improvement was Floyd-Warshall algo. this is a bad-ass implementation highly complciated coding, but still took 3 mins, did not even submit. http://en.wikipedia.org/wiki/Floyd_Warshall The next improvement was k-d tree. this implementation is dynamic programming. it divides the n-dimensional space to x planes and y planes. I really liked the implementation, but still it took 40 sec. http://en.wikipedia.org/wiki/K-d_tree check out the cool animation for the Nearest Neighbour Search. Finally, the actual algorithm I used is quite simple. But k-d trees sent me in the direction. I will not divulge it for now, since someone out there could be still trying and it's not fair to them. The material I read all through the last week was simply outstanding and it is all free! It's amazing how much stuff one can learn now free. If only we had this internet while we were in school. Some of the material I used: Stumbled on this amazing site, bought his book now, currently shipping: http://www.cs.sunysb.edu/~algorith/video-lectures/ Stanford lectures on Algorithms http://academicearth.org/lectures/search/min-sum%20algorithm / Also bought this box set: http://www.amazon.com/Art-Computer-Programming-Volumes-Boxed /dp/0201485419 Used mostly Java and Python for some prototyping. In the meantime, the InterviewStreet guys contacted me and asked me what companies I will be interested in working! They said, just tell us where you want to work, we will forward the stuff and all that! It is so amazing really!! And these guys at Interview Street are bunch of hardcore CS guys and very very smart!! I will take a couple of days break before I start looking at the 4th. the 3rd was so mentally exhausting. ".. be fearful when others are greedy and be greedy only when others are fearful." - Warren Buffett | ||
| Entikaburlu Junior Artist Username: Entikaburlu Post Number: 713 Registered: 07-2011 Posted From: 67.247.83.224 Rating: N/A |
Problem #4 is posted. We are currently tied for 13th position now with 3 solved. ".. be fearful when others are greedy and be greedy only when others are fearful." - Warren Buffett |
