2020 USACO January Contest -- Final Results

The 2020 USACO January Contest featured algorithmic programming problems covering a wide range of techniques and levels of difficulty.

A total of 6498 distinct users logged into the contest during its 4-day span. A total of 5531 participants submitted at least one solution, hailing from 81 different countries:

 3146 USA 1132 CHN  215 KOR  129 CAN   82 MYS   59 ROU   59 IND
   49 BLR   40 VNM   39 GEO   33 FRA   32 RUS   26 SGP   26 SAU
   25 MNG   25 IRN   22 POL   21 UKR   21 MEX   20 TWN   20 CUB
   19 KAZ   18 DEU   16 GBR   16 ARM   14 COL   14 AUS   13 BGD
   12 SLV   11 SYR   11 JPN   11 HKG   10 TUR   10 HRV    9 TJK
    9 LTU    8 KGZ    8 BRA    7 NZL    6 ZAF    6 EST    5 NLD
    5 HUN    5 GRC    5 ESP    4 ITA    3 SRB    3 NGA    3 IDN
    3 FIN    3 EGY    3 BGR    3 BEL    3 AZE    2 UZB    2 TUN
    2 THA    2 PSE    2 PHL    2 CHE    2 ARE    1 ZWE    1 TUV
    1 TKM    1 PRT    1 PRK    1 PAK    1 OMN    1 MDA    1 KIR
    1 JAM    1 ISR    1 IRL    1 GUM    1 GIN    1 CZE    1 CYP
    1 CMR    1 BOL    1 BIH    1 ARG
In total, there were 13483 graded submissions, broken down by language as follows:

 4552 C++11
 4428 Java
 2749 C++
 1526 Python 3.4.0
  147 Python 2.7.6
   70 C
   11 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 2020 January Contest, Platinum

The platinum division had 503 total participants, of whom 341 were pre-college students. Results for top scorers are here. Congratulations to all of the top participants for their excellent results!

1

Cave Paintings
View problem  |   Test data   |   Solution

2

Non-Decreasing Subsequences
View problem  |   Test data   |   Solution

3

Falling Portals
View problem  |   Test data   |   Solution

USACO 2020 January Contest, Gold

The gold division had 851 total participants, of whom 662 were pre-college students. All competitors who scored 650 or higher on this contest are automatically promoted to the platinum division. Detailed results for all those promoted are here.

1

Time is Mooney
View problem  |   Test data   |   Solution

2

Farmer John Solves 3SUM
View problem  |   Test data   |   Solution

3

Springboards
View problem  |   Test data   |   Solution

USACO 2020 January Contest, Silver

The silver division had 2047 total participants, of whom 1617 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.

1

Berry Picking
View problem  |   Test data   |   Solution

2

Loan Repayment
View problem  |   Test data   |   Solution

3

Wormhole Sort
View problem  |   Test data   |   Solution

USACO 2020 January Contest, Bronze

The bronze division had 3570 total participants, of whom 2740 were pre-college students. All competitors who scored 750 or higher on this contest are automatically promoted to the silver division. Detailed results for all those promoted are here.

1

Word Processor
View problem  |   Test data   |   Solution

2

Photoshoot
View problem  |   Test data   |   Solution

3

Race
View problem  |   Test data   |   Solution

Final Remarks

I'm happy to see continued high levels of participation in this second contest of the 2019-2020 season. At its peak, about two IOIs worth of competitors were currently taking the contest! There is a great deal of computing talent out there -- many promotions and many high scores.

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 Mark Gordon, Benjamin Qi, Dhruv Rohatgi, Nick Wu, Travis Hance, Nathan Pinsker, Richard Peng, Daniel Zhang, Spencer Compton, Eric Zhang, Mark Chen, and Chris 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: TwoSigma, D.E. Shaw, and Ansatz Trading.

We look forward to seeing everyone again for the February contest.

Happy coding!

- Brian Dean ([email protected])
Director, USACO