Four teams from the University of Helsinki made it to the top ten in the Nordic Collegiate Programming Contest, NCPC 2015.

 

A total of 307 teams from Finland, Sweden, Norway, Denmark, and Iceland competed in the NCPC on Saturday, 10 October. The competing teams attempted to solve ten problems by implementing a functional algorithm for each problem. The teams have a total of five hours to solve the problems.

 

 

The problems were interesting and their level of difficulty increased suitably, said Helsinki University coach Antti Laaksonen. Only one of the problems was such that not one of the teams could solve it in the time given. The problem was by no means impossible, but the short time limit of the contest makes the problem solving more challenging than usual. The unsolved problem went like this:

 You are at home and about to drive to work.  The road you will take is a straight line with no speed limit. There are, however, traffic lights precisely every kilometer, and you can not pass a red light. The lights change instantaneously between green and red, and you can pass a light whenever it is green. You can also pass through a light at the exact moment of changing colour.  There are no traffic lights at the start or the end of the road.

Now your car is special; it is an iCar, the first Orange car, and it has only one button. When you hold down the button, the car accelerates at a constant rate of1m/s²; when you release the button the car stops on the spot. You have driven to work many times, so you happen to know t schedules of the traffic lights.   Now the question is,  how quickly can you get to work?       

 

The top of the contest was dominated by the University of Helsinki from Finland and Kungliga Tekniska Högskolan from Sweden.

 

The success of both the UH and KTH is based on a lot of practice, says Antti Laaksonen. Both universities have a strong algorithm community, with members who are interested in using computers to solve problems. The communities include current and former undergraduates, as well as lower and upper-secondary students. Their common goal is to learn the design and programming of algorithms in depth, which develops with long-running practice.

 

One of the significant meeting spaces for the algorithm community is the Kumpula campus at UH, where an algorithm club meets on Fridays at 17:30-19:30 during the school year. The club is organised in the Linkki classroom (Exactum building, C221), and all interested comers are welcome to attend.

 

The contest problems:: https://ncpc15.kattis.com/problems