2023 US Open Contest -- Final Results

The 2023 US Open contest featured algorithmic programming problems covering a wide range of techniques and levels of difficulty.

A total of 6672 distinct users logged into the contest during its 4-day span. A total of 4913 participants submitted at least one solution, hailing from 74 different countries:

 2751 USA 1341 CHN  147 CAN   99 KOR   54 IND   43 ISR   36 DEU
35 SGP   29 ROU   27 ARM   25 EGY   23 TWN   21 VNM   20 AUS
19 POL   17 GBR   14 HKG   12 FRA   11 TUR   11 SLV   11 GEO
9 MYS    8 TUN    8 NZL    8 MNG    7 UZB    7 SYR    7 JPN
7 BRA    6 CHE    5 ZAF    5 UKR    5 KGZ    5 BGD    4 RUS
4 KAZ    4 FIN    4 AZE    3 THA    3 PER    3 PAK    3 NLD
3 IRL    3 IDN    3 GRC    3 BLR    3 BGR    2 TKM    2 SRB
2 SAU    2 NGA    2 MEX    2 IRN    2 ETH    2 EST    2 CUB
2 COL    1 SVK    1 REU    1 PRK    1 PHL    1 MLT    1 MKD
1 LTU    1 LKA    1 KWT    1 KHM    1 ITA    1 ISL    1 ESP
1 COD    1 CHL    1 ARE    1 AFG

In total, there were 10724 graded submissions, broken down by language as follows:

 5573 C++17
1878 C++11
1862 Java
1360 Python 3.6.9
38 C
13 Python 2.7.17


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 2023 US Open Contest, Platinum

The platinum division had 396 total participants, of whom 280 were pre-college students. Results for top scorers are here. Congratulations to all of the top participants for their excellent results!

1

Pareidolia
View problem  |   Test data   |   Solution

2

Good Bitstrings
View problem  |   Test data   |   Solution

3

Triples of Cows
View problem  |   Test data   |   Solution

USACO 2023 US Open Contest, Gold

The gold division had 880 total participants, of whom 648 were pre-college students. All competitors who scored 750 or higher on this contest are automatically promoted to the platinum division. Detailed results for all those promoted are here.

1

Custodial Cleanup
View problem  |   Test data   |   Solution

2

Pareidolia
View problem  |   Test data   |   Solution

3

Tree Merging
View problem  |   Test data   |   Solution

USACO 2023 US Open Contest, Silver

The silver division had 2610 total participants, of whom 2071 were pre-college students. All competitors who scored 750 or higher on this contest are automatically promoted to the gold division. Note that due to an unintended weakness in some of the test data for the "field day" problem, data was adjusted and submissions for this problem were re-graded; promotions were granted in this case to those who passed the cutoff either before or after the re-grade (bear in mind that it is always a possibility that test data may need to be adjusted after a contest ends).

1

Milk Sum
View problem  |   Test data   |   Solution

2

Field Day
View problem  |   Test data   |   Solution

3

Pareidolia
View problem  |   Test data   |   Solution

USACO 2023 US Open Contest, Bronze

The bronze division had 2960 total participants, of whom 2313 were pre-college students. All competitors who scored 750 or higher on this contest are automatically promoted to the silver division.

2

Moo Language
View problem  |   Test data   |   Solution

3

Rotate and Shift
View problem  |   Test data   |   Solution

Final Remarks

The completion of the US Open contest wraps up our 2022-2023 season, which I'm happy to see had both strong participation and strong results. Looking at recent challenges and trends in computing, there has never been a greater need for those with strong computational problem-solving skills. Looking at our contest results, it is encouraging to see such a strong pipeline of future talent.

For those not yet promoted, remember that the more practice you get, the better your algorithmic coding skills will become -- please keep at it! USACO contests are designed to challenge even the very best students, and it can take a good deal of hard work to excel at them. 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 William Yue, Claire Zhang, Chongtian Ma, Brandon Wang, Benjamin Qi, Eric Yachbes, Aryansh Shrivastava, Danny Mittal, Nathan Wang, Richard Qi, David Hu, and Spencer Compton. 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: Citadel, Ansatz, X-Camp, TwoSigma, VPlanet Coding, EasyFunCoding, Orijtech, and Jump Trading.

We look forward to seeing everyone again at the start of the next season. Please wish us luck in our training camp and as we compete in the IOI and EGOI this year!

Happy coding!

- Brian Dean (bcdean@clemson.edu)
Professor and Director, School of Computing, Clemson University
Director, USACO