2018 US Open Contest -- Final Results

This was our final contest of the 2017-2018 season, and also our national championship contest, which typically carries high weight during selection of finalists to attend our summer training camp. With a 5-hour duration, it featured problems that were intended to be challenging at all levels.

A total of 2266 distinct users logged into the contest during its 4-day span. A total of 1960 participants submitted at least one solution, hailing from 59 different countries:

 1330 USA  229 CHN   50 GEO   29 CAN   24 BLR   23 UKR   20 TWN
   18 IND   15 FRA   15 ARM   14 VNM   14 IDN   13 KOR   10 IRN
    9 ROU    9 MYS    9 IRL    9 COL    8 BGD    7 POL    7 FIN
    7 BGR    6 ZAF    6 TUR    6 JPN    6 GRC    5 RUS    5 KAZ
    5 GBR    5 DEU    4 HRV    4 CUB    4 AUS    3 TUN    3 MEX
    3 EST    2 TKM    2 NZL    2 CMR    1 VEN    1 UGA    1 THA
    1 SYR    1 SVN    1 SGP    1 PHL    1 PAK    1 NPL    1 NLD
    1 MNG    1 LVA    1 LTU    1 HUN    1 HKG    1 GIN    1 EGY
    1 CZE    1 BRA    1 ARG

In total, there were 4974 graded submissions, broken down by language as follows:

 2074 Java
 1603 C++11
  941 C++
  234 Python 3.4.0
   70 Python 2.7.6
   33 C
   19 Pascal

Below are the detailed results for each of the platinum, gold, silver, and bronze contests. You will also find solutions and test data for each problem, and by clicking on any problem you can practice re-submitting solutions in "analysis mode". If you are logged in, you will also see your own specific results below alongside the contest(s) you took.

USACO 2018 US Open Contest, Platinum

The platinum division had 393 total participants, of whom 319 were pre-college students. There were no perfect scores in the pre-college division, due to the challenging "train" problem, but there were a number of impressively-high scores. Since scores tended to be clumped together a bit, a few more test cases were added to the "train" and "disrupt" problems after the contest ended to try and improve differentiation in scores (although not common to date, recall that our rules do allow adjustments in test data after the contest ends if deemed necessary by the coaches). In the observer category, we did have two perfect scores, Antonio Molina from Canada and Erik-Jan Krijgsman from the Netherlands.

Results for top scorers are here. Congratulations to all of the top participants for their excellent results!

Note: Platinum results were re-graded a day after they were announced after we needed to fix a small issue with some of the later test cases in the "disrupt" problem.

USACO 2018 US Open Contest, Gold

The gold division had 425 total participants, of whom 368 were pre-college students. All competitors who scored 700 or higher on this contest are automatically promoted to the platinum division. Detailed results for all those promoted are here.

USACO 2018 US Open Contest, Silver

The silver division had 732 total participants, of whom 645 were pre-college students. All competitors who scored 700 or higher on this contest are automatically promoted to the gold division. Detailed results for all those promoted are here.

USACO 2018 US Open Contest, Bronze

The bronze division had 812 total participants, of whom 657 were pre-college students. All competitors who scored 700 or higher on this contest are automatically promoted to the silver division. Detailed results for all those promoted are here.

Final Remarks

I'm quite happy with results from this season, as they indicate that our pipeline of computational talent in the USA remains stronger than ever. Given the strong performances we've seen from our top students, I expect training camp this summer should be quite thrilling.

As in the past, the US Open contest was designed to challenge the very best students -- at all levels, not just in platinum. From the results, it looks like this was indeed the case, and it is good to see that many rose to the challenge and scored quite well. For those not yet promoted, remember that the more practice you get, the better your algorithmic coding skills will become -- please keep at it! To help you fix any bugs in your code, you can now re-submit your solutions and get feedback from the judging server using "analysis mode".

A large number of people contribute towards the quality and success of USACO contests. Those who helped with this contest include Jay Leeds, Dhruv Rohatgi, Travis Hance, Matt Fontaine, and Mark Chen. I'd like to personally acknowledge Dhruv in particular for all the outstanding problems he has contribted this season. Thanks also to our translators and to Clemson CCIT for providing our contest infrastructure. Finally, we are grateful to the USACO sponsors for their generous support: D.E. Shaw, Jump Trading, and Ansatz Capital.

Thank you all for a wonderful season. Wish us luck at the IOI in Japan this summer!

Happy coding!

- Brian Dean ([email protected])
Director, USA Computing Olympiad
Associate Professor of Computer Science, Clemson University

Your Account