2024 January Contest -- Final Results

The 2024 January contest featured algorithmic programming problems covering a wide range of techniques and levels of difficulty.

A total of 12746 distinct users logged into the contest during its 4-day span. A total of 10101 participants submitted at least one solution, hailing from 125 different countries:

 4725 USA 3375 CHN  354 CAN  261 KOR  131 ROU  108 IND   78 MYS
   77 SGP   64 HKG   57 TWN   46 DEU   44 GBR   44 AUS   40 SYR
   34 TUR   33 POL   32 ISR   30 AZE   26 GEO   26 EGY   26 BLR
   23 VNM   21 JPN   20 BRA   17 KAZ   17 ABW   16 IRN   15 SLV
   15 FRA   15 COL   15 ARM   14 BOL   13 IDN   12 SAU   12 CUB
   11 UZB   10 THA   10 NZL   10 MEX   10 ESP   10 BGD    9 PAK
    8 ZAF    8 RUS    8 ARG    7 SWE    7 NLD    5 UKR    5 EST
    5 CHL    5 AUT    5 ATG    5 AFG    4 SRB    4 MKD    4 KGZ
    4 GRC    4 BEL    4 ARE    4 AND    3 ZWE    3 UMI    3 TUN
    3 PHL    3 ANT    3 ALB    3 ALA    3 AGO    2 VIR    2 TKM
    2 PRK    2 NPL    2 NER    2 MNG    2 MLT    2 MAC    2 LTU
    2 ITA    2 IRL    2 HRV    2 GHA    2 FIN    2 CMR    2 CHE
    2 BWA    2 ASM    1 YEM    1 VGB    1 VAT    1 TZA    1 TKL
    1 TJK    1 SEN    1 QAT    1 PSE    1 PER    1 NOR    1 MMR
    1 MDA    1 MCO    1 MAR    1 LAO    1 KHM    1 KEN    1 JEY
    1 IMN    1 HUN    1 HTI    1 GIB    1 FSM    1 DNK    1 CZE
    1 CYP    1 CXR    1 CRI    1 CCK    1 CAF    1 BTN    1 BRN
    1 BLZ    1 BIH    1 BHR    1 BGR    1 BDI    1 ATF
In total, there were 26414 graded submissions, broken down by language as follows:

13779 C++17
 4504 C++11
 4018 Python-3.6.9
 3975 Java
  117 C
   21 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 2024 January Contest, Platinum

The platinum division had 489 total participants, of whom 347 were pre-college students. Results for top scorers are here. Congratulations to all of the top participants for their excellent results!

1

Island Vacation
View problem  |   Test data   |   Solution

2

Merging Cells
View problem  |   Test data   |   Solution

3

Mooball Teams III
View problem  |   Test data   |   Solution

USACO 2024 January Contest, Gold

The gold division had 940 total participants, of whom 641 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. Note: test cases 11-15 for problem 2 were unfortunately originally broken during the contest, since they involved higher values of N and C than the problem statement guaranteed. These cases were corrected and all submissions were re-graded; no promotions were affected by the change.

1

Walking in Manhattan
View problem  |   Test data   |   Solution

2

Cowmpetency
View problem  |   Test data   |   Solution

3

Nap Sort
View problem  |   Test data   |   Solution

USACO 2024 January Contest, Silver

The silver division had 3920 total participants, of whom 2956 were pre-college students. All competitors who scored 750 or higher on this contest are automatically promoted to the gold division.

1

Cowmpetency
View problem  |   Test data   |   Solution

2

Potion Farming
View problem  |   Test data   |   Solution

3

Cowlendar
View problem  |   Test data   |   Solution

USACO 2024 January Contest, Bronze

The bronze division had 8454 total participants, of whom 6556 were pre-college students. All competitors who scored 750 or higher on this contest are automatically promoted to the silver division.

1

Majority Opinion
View problem  |   Test data   |   Solution

2

Cannonball
View problem  |   Test data   |   Solution

3

Balancing Bacteria
View problem  |   Test data   |   Solution

Final Remarks

From a scientific standpoint, the January 2024 contest went well, with strong problem lineups in all divisions, and healthy numbers of students being promoted. The contest was unfortunately marred by a massive denial of service attack we experienced at two separate moments during the contest, which interfered with the contest operation for a substantial number of competitors. As a result, we are working on migrating to a new hosting platform with more robust countermeasures against this sort of situation. For those affected by these outages, we understand and share your frustration. Unfortunatley, our general policy regarding outages beyond our control does not allow us to provide extra time for those affected, stemming from the need to preserve the integrity of our contests, which do serve as a selection mechanism for the USA IOI and EGOI teams. For USA pre-college platinum participants: since the certified platinum window was unaffected, scores from this contest will count, and during finalist selection, our coaches will be sure not to penalize non-certified platinum scores that were possibly compromised by outages in this contest. For example, 3 certified scores plus a potentially compromised non-certified score on this contest will receive full consideration.

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, Dhruv Rohatgi, Nick Wu, Suhas Nagar, Rohin Garg, Brandon Wang, Rain Jiang, Danny Mittal, Timothy Qian Anand John, Ben Chen, Andi Qu, Bing-Dong Liu, Richard Qi, Andrew Gu, Claire Zhang, Nathan Wang, 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 for the 2024 February contest.

Happy coding!

- Brian Dean
Professor and Director, School of Computing, Clemson University
Director, USACO