## 2022 US Open Contest -- Final Results

The 2022 US Open contest featured algorithmic programming problems covering a wide range of techniques and levels of difficulty.

A total of 6024 distinct users logged into the contest during its 4-day span. A total of 4529 participants submitted at least one solution, hailing from 69 different countries:

 2686 USA 1041 CHN  132 CAN   98 KOR   74 IND   33 TWN   33 SGP
33 ISR   31 POL   25 VNM   25 GEO   23 IRN   20 HKG   19 IDN
19 ARM   15 ROU   15 DEU   14 BGD   13 RUS   11 GBR   10 SAU
10 MYS   10 FRA    8 TUN    8 SLV    8 AUS    7 JPN    6 PHL
6 KAZ    5 TUR    5 NZL    5 KGZ    5 EST    5 CHE    5 BRA
5 AZE    4 ZAF    4 NGA    4 MEX    4 ESP    3 UKR    3 MNG
3 LKA    3 BGR    2 THA    2 SYR    2 SWE    2 ITA    2 IRQ
2 FIN    2 BEL    2 ARE    1 VEN    1 UZB    1 SRB    1 PSE
1 PRK    1 NPL    1 NLD    1 MKD    1 MDA    1 LUX    1 ISL
1 HRV    1 GUM    1 EGY    1 CZE    1 CMR    1 BLR

In total, there were 10635 graded submissions, broken down by language as follows:

 4590 C++17
2572 Java
2140 C++11
1267 Python 3.6.9
52 C
14 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.

NOTE: For this contest, as with the previous contest, sample test cases are no longer being counted towards one's score.

## USACO 2022 US Open Contest, Platinum

The platinum division had 433 total participants, of whom 308 were pre-college students. Results for top scorers are here. Congratulations to all of the top participants for their excellent results!

# 1

262144 Revisited
View problem  |   Test data   |   Solution

# 2

Hoof and Brain
View problem  |   Test data   |   Solution

# 3

Up Down Subsequence
View problem  |   Test data   |   Solution

## USACO 2022 US Open Contest, Gold

The gold division had 903 total participants, of whom 680 were pre-college students. All competitors who scored 800 or higher on this contest are automatically promoted to the platinum division. Detailed results for all those promoted are here.

# 1

Apple Catching
View problem  |   Test data   |   Solution

# 2

Pair Programming
View problem  |   Test data   |   Solution

# 3

Balancing a Tree
View problem  |   Test data   |   Solution

## USACO 2022 US Open Contest, Silver

The silver division had 2449 total participants, of whom 1978 were pre-college students. All competitors who scored 800 or higher on this contest are automatically promoted to the gold division.

# 1

Visits
View problem  |   Test data   |   Solution

# 2

Subset Equality
View problem  |   Test data   |   Solution

# 3

COW Operations
View problem  |   Test data   |   Solution

## USACO 2022 US Open Contest, Bronze

The bronze division had 2604 total participants, of whom 2063 were pre-college students. All competitors who scored 700 or higher on this contest are automatically promoted to the silver division.

# 1

Photoshoot
View problem  |   Test data   |   Solution

# 2

Counting Liars
View problem  |   Test data   |   Solution

# 3

Alchemy
View problem  |   Test data   |   Solution

### Final Remarks

The US Open contest is our final contest of the 2021-2022 season, serving as our "national championship" and receiving high weight during selection of finalists to attend our 2022 summer training camp. The contest ran smoothly and despite a number of relatively difficult problems, we saw impressive scores across all four divisions, and reasonably high numbers of promotions.

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 Benjamin Qi, Danny Mittal, Michael Cao, Ray Bai, Andrew Wang, Aryansh Shrivastava, Jesse Choe, Nick Wu, Richard Qi, Andi Qu, Spencer Compton, Mark Chen, Jichao Qian, and Daniel Zhang. 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, EasyFunCoding, and Jump Trading.

We hope you enjoyed the 2021-2022 season and look forward to seeing everyone again in fall 2022!

Happy coding!

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