tkh’s blog

Topcoder coding competition

Last night we had a coding competition at school sponsored by topcoder.com. I was able to solve the first problem in 15 minutes, but it took me so long to solve the second problem. The second problem is to find the largest triangle from a set of colored points in 3D space. The triangle must be formed by vertices with the same color or with different colors. The algorithm to find the triangle is very simple because you just need to have three nested for loop in x, y, and z components. To me the problem was finding a formula to find the area of a triangle. I tried using Heron’s formula, but the one I remembered was wrong. I didn’t know I can look up websites during the competition, so I didn’t. Unfortunately the formula was wrong and that was the only flaw in my program. I ended up being the fourth place in the competition. The first place gets an iPod, the second one gets an mp3 player, and the third one gets $50 credit to the university’s account. I was pissed off so much. If I had gotten the formula right, I would have been able to be the third place at least.

In this morning, I got an email from the student who is a liaison for the competition. He said that the person got the second place is not eligible because he is an alum. So I became the third place. I’m still not staisfied with my score, but at least I get a prize.

Ken Perlin

Ken Perlin of Perlin noise fame came to the computer graphics class where I’m doing TA today. He talked about various stuff he’s worked on. You can look at his works by searching “perlin” at google and follow the top ranked link (this is what he said in class to get to his webpage).

Class

I covered the first lecture for the advanced graphics class since my advisor is out of town. I showed students the demos so they can grab the ideas on what will be covered in the class and the term project. They all seemed to be interested in vertex/fragment shaders.

Finished…

Finally I finished the final exam. It was very hard and one problem was elusive, but somehow I got a solution and just wrote it up. I think around 25% of enrolled students will pass this course. I hope to be in this group. Yes, it’s a pretty hard class. Anyway the semester is over. Now I play the computer game!

dia

I’ve been working on the take home exam for the algorithms class, and drew a diagram with dia. When I tried to export it to EPS file, it crashed. I thought it may be some gnome issue, so I installed the plane gtk version of dia and tried the same thing, but crashed. I was so frustrated. I exported the diagram to fig format so I can do the conversion in xfig. When I loaded the diagram in xfig, all the texts were converted to Courier font, and line properties can’t be edited in xfig. Now I have to draw the diagram again. Bummer!

Getting harder…

Looks like I’m getting tied up with school work. Probably I will have a take home exam that ends in a week tomorrow, I have to turn in a short paper by Friday, and I still have a homework due tomorrow. The good thing is that I don’t have to take an exam for the programming language systems class because I did well on homework and the project. Hope I can manage the remaining work well.

Flu

Flu is attacking the town. Yesterday, there was an article on DailyLobo that over a hundred of students having flu come to the student health center everyday. I’ve seen lots of people coughing. I really don’t want to get flu, so I stop breathing if I find person coughing, and quickly leave the place. I don’t know if a flu shot is effective, but I’ll take a shot if the situation gets worse.

Parking

I went to the pool this evening, but the parking lot was full and there were many elderly people walking to Popejoy Hall. Whenever there is a performance or something at Popejoy Hall, it’s going to be very hard to find a parking space. I was looking for a space all the way down to the dorm area, but there was no space. So I made U-turn and drove to the Biology department building, a relatively remote place, but it was all full. I was so pissed off, and about to give up today’s exercise and thinking about getting food. Before leaving campus, I went back again to the parking lot near the pool, and luckily enough I managed to find a space. So I was able to swim this evening, but why people without parking permits can park? Parking enforcement is effective till 8pm, so they should be ticketed. They have designated parking space in north part of campus and shuttle buses are available. They shouldn’t bother students with valid parking permits. The parking problem might be improved when the six story parking structure which is currently under construction is open, but I have to deal with this difficult situation for a while. Sigh…

Airport

About a week ago, I noticed that I can register MAC addresses to use WiFi on campus. So I registered the MAC address of my Airport card and got the WEP key, and tried to use the Airport card in the SUB building on campus, but I couldn’t get it working. The WEP authentication seems to success and I get decent level of signal, but I can’t ping to other hosts at all. I went over to the help desk, but they weren’t able to fix the problem. A senior tech support guy told me that he saw some 12″ PowerBooks can’t get Airport working. He also brought his 15″ PowerBook and checked if it works. It worked, but the OS was 10.2. So he rebooted into 10.3 and this time, it didn’t work at the first attempt. He checked various options and finally got it working. I tried to set the same options as his PB, but I wasn’t able to get it working. After an hour of struggling with configurations, we gave up and he issued a tech support ticket so he can work on it and give me feedback. I don’t know what’s wrong, since I can use the Airport in CS department. Until this issue is fixed, I have to carry an Ethernet cable. It’s so frustrating…

Lambda Calculus

Finally finished implementing a lambda calculus interpreter in Ciao Prolog. It has the web interface and the code is written entirely in Prolog, including the CGI stuff. I can go somewhere to refresh my brain on the last day of Thanksgiving holiday!