## 2019 January Contest -- Final Results

The 2019 January contest featured algorithmic programming problems covering a wide range of techniques and levels of difficulty.

A total of 4953 distinct users logged into the contest during its 4-day span. A total of 4249 participants submitted at least one solution, hailing from 74 different countries:

 2623 USA  633 CHN   79 CAN   69 KOR   63 RUS   62 MYS   56 ROU
51 VNM   51 IND   47 BLR   36 UKR   34 BGD   33 GEO   30 FRA
24 TWN   22 MNG   22 KAZ   19 ARM   18 MEX   15 IRN   15 AUS
14 TUR   13 TUN   13 POL   13 DEU   12 SGP   12 HRV   11 GBR
10 COL    9 ZAF    9 SLV    9 BGR    8 HUN    7 CUB    6 TKM
6 LTU    6 IDN    6 AZE    5 SYR    4 TJK    4 NLD    4 JPN
4 ITA    3 THA    3 SWE    3 SRB    3 MDA    3 MAR    3 HKG
3 FIN    3 CMR    3 BIH    3 BEL    2 SAU    2 NZL    2 NGA
2 KGZ    2 ISR    2 IRL    2 EST    2 ESP    2 DOM    2 BRA
2 ARG    1 UZB    1 SVN    1 PRT    1 PHL    1 NPL    1 KEN
1 IRQ    1 BHS    1 ATG    1 ABW

In total, there were 12292 graded submissions, broken down by language as follows:

 4407 Java
4186 C++11
2254 C++
1175 Python 3.4.0
197 Python 2.7.6
67 C
6 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 2019 January Contest, Platinum

The platinum division had 525 total participants, of whom 380 were pre-college students. Overall, we saw 21 perfect scores, with 5 from the USA. Full results are here. Congratulations to all of the top participants for their excellent results!

# 1

Redistricting
View problem  |   Test data   |   Solution

# 2

Exercise Route
View problem  |   Test data   |   Solution

# 3

Train Tracking 2
View problem  |   Test data   |   Solution

## USACO 2019 January Contest, Gold

The gold division had 988 total participants, of whom 812 were pre-college students. Despite a challenging problem line-up, we saw many very high scores in this contest. 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

Cow Poetry
View problem  |   Test data   |   Solution

# 2

Sleepy Cow Sorting
View problem  |   Test data   |   Solution

# 3

Shortcut
View problem  |   Test data   |   Solution

## USACO 2019 January Contest, Silver

The silver division had 1826 total participants, of whom 1511 were pre-college students. All competitors who scored 750 or higher on this contest are automatically promoted to the gold division. Detailed results for all those promoted are here.

# 1

Grass Planting
View problem  |   Test data   |   Solution

# 2

Icy Perimeter
View problem  |   Test data   |   Solution

# 3

Mountain View
View problem  |   Test data   |   Solution

## USACO 2019 January Contest, Bronze

The bronze division had 2537 total participants, of whom 2037 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

Shell Game
View problem  |   Test data   |   Solution

# 2

Sleepy Cow Sorting
View problem  |   Test data   |   Solution

# 3

Guess the Animal
View problem  |   Test data   |   Solution

### Final Remarks

Halfway through the 2018-2019 season already! Overall this was a another successful contest. There were a few minor test data issues at the beginning of day 1 that were quickly corrected, but otherwise things ran smoothly from a technical perspective. Score distributions all look reasonable.

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 Dhruv Rohatgi (who designed the entire platinum problem set!), Dhruv Rohatgi (probably doesn't hurt to thank him twice), Nick Wu, Jay Leeds, Franklyn Wang, Mark Chen, Matt Fontaine, Spencer Compton, and Daniel Chiu. 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. We are still actively looking for additional sponsors who might be interested in supporting our efforts to contribute to the computing talent pipeline -- please feel welcome to send me a note if you know any good prospects I should consider contacting.

We look forward to seeing everyone again for the 2019 February contest.

Happy coding!

- Brian Dean (bcdean@clemson.edu)
Director, USA Computing Olympiad