USACO February 2013 Contest -- Final Results

The USACO February 2013 contest featured algorithmic programming problems covering a wide range of techniques and levels of difficulty.

Click here to see the contest problems and official solutions, or to practice re-submitting solutions.

A total of 1122 participants submitted at least one solution, hailing from 64 different countries:

 489 USA  62 BLR  51 CHN  32 IRN  31 VNM  30 CAN  25 TUR
  21 RUS  20 KAZ  17 ITA  17 ARM  16 MYS  16 GEO  16 BGR
  14 VEN  14 KOR  13 MEX  13 IND  12 ROU  12 DEU  11 CUB
  10 UKR   9 TKM   9 POL   9 MKD   9 AUS   8 TJK   8 GRC
   7 SRB   7 LTU   7 IDN   6 JPN   6 GBR   6 DOM   6 COL
   6 BGD   5 ZAF   5 NLD   5 LVA   5 FRA   5 AZE   4 YUG
   3 TWN   3 THA   3 SVK   3 SGP   3 ISR   3 HRV   3 EST
   2 MDA   2 HKG   2 ESP   2 CYP   2 BRA   2 BIH   2 BEL
   2 ARG   1 ZWE   1 RSA   1 MDG   1 HUN   1 CZE   1 BDI
   1 AUT

The average participant submitted solutions for 2.5 problems. In total, there were 2808 graded submissions, broken down by language as follows:

1696 C++
 768 Java
 243 Pascal
  61 Python
  38 C

Gold Division Results

The Gold division had 211 total participants, of whom 170 were pre-college students.

Full Gold Results

We had some fantastic results this time in the gold division, with 12 total perfect scores (9 in the pre-college category, and 3 observers). Perfect scores in the pre-college category were:

Country   Grad   Name Score
KOR  2015    Seokhwan Choi1000
USA  2015    Andrew He1000
RUS  2014    Nikolay Kalinin1000
VNM  2014    Nguyễn Quang Dũng1000
LVA  2013    Ojārs Vilmārs Ratnieks1000
USA  2014    Joshua Brakensiek1000
USA  2015    Scott Wu1000
USA  2014    Steven Hao1000
USA  2013    Ray Li1000

Perfect scores in the observer group included:

Country   Name Score
NLDJosse Dobben1000
GBRRobin Lee1000
UKRYaroslav Tverdokhlib1000

Congratulations to these and all other high-scoring participants!

Silver Division Results

The silver division had 232 total participants, of whom 193 were pre-college students.

Full Silver Results

Scores in the silver division were also quite impressive, with 6 perfect pre-college scores:

Country   Grad   Name Score
VNM  2013    Anh Nguyễn Tuấn1000
TWN  2013    Robert Huang1000
MKD  2015    Vasil Kuzevski1000
RUS  2013    Artem Rakhov1000
POL  2014    Jarosław Dzikowski1000
MKD  2015    Kliment Serafimov1000

and also 5 perfect observers:

Country   Name Score
COLAlejandro Alejandro1000
CHNYang Cao1000
USAJason Li1000
ROUGeorge Marcus1000
JPNMinoru Fujita1000

All participants with scores at least 700 will be automatically promoted to the gold division for future contests.

Bronze Division Results

A total of 686 participants competed in the bronze division, 564 of them pre-college students.

Full Bronze Results

The bronze contest this time around proved to be much more approachable than in the January contest. Congratulations to the following 33 students achieving perfect scores in the pre-college group!

Country   Grad   Name Score
KOR  2016    수찬 박1000
TJK  2013    Ibrohim Jamshed1000
GRC  2014    Jeffrey Tobin1000
USA  2015    Yang Liu1000
DEU  2013    Lucas Elbert1000
USA  2013    Colin Wei1000
KOR  2015    Taeho Gwon1000
CHN  2015    Steven Du1000
POL  2017    Paweł Burzyński1000
JPN  2013    Kent Nikaido1000
TUR  2015    Ikbal Kazar1000
MYS  2014    Si Wei How1000
CHN  2014    Nasri D1000
IRN  2013    Mohammad Amin Khashkhashi Moghaddam1000
USA  2018    Dhruv Rohatgi1000
USA  2014    Paul Cruz1000
USA  2015    Brice Huang1000
ROU  2014    Radu Szasz 1000
BLR  2014    Egor Kazachenko1000
ARM  2013    Karen Hambardzumyan1000
ROU  2014    Tudor Tiplea1000
IRN  2015    Kiarash Korki1000
USA  2013    Jeffrey Yuan1000
MYS  2013    SiYu How1000
IRN  2014    Pedram Hashemi1000
USA  2018    Nicholas Sun1000
USA  2016    Michael Colavita1000
USA  2016    Sean Shi1000
RUS  2013    Edvard Davtyan1000
RUS  2014    Maxim Gusarov1000
RUS  2013    Ilya Peresadin1000
RUS  2015    Igor Kudryashov1000
BLR  2013    Artyom Kazak1000

Also a round of congratulations to the observers with perfect scores:

Country   Name Score
CHNYilun Wu1000
RUSAlexey Safronov1000
NLDRaymond van Bommel1000
MEXIgnacio Gutierrez1000
USAWeixin Guo1000
NLDMathijs van de Nes1000
BLRYanush Piskevich1000
IRNAli Pournaghi1000
CHNIru Cai1000
KORJoon Young Seo1000
RUSNikita Durynin1000
CANLawson He1000

All participants with scores at least 850 will be automatically promoted to the silver division for future contests.

Final Remarks

With slightly higher participation than the January contest, everything seems to have run smoothly with the February contest. Score distributions were quite reasonable, and I was especially glad to see that the level of difficulty in bronze was back to a more reasonable state, after two very challenging bronze contests in December and January. Many participants are still being promoted to higher divisions. 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, Richard Peng, Travis Hance, Bruce Merry, Fatih Gelgi, Jonathan Paulson, Yan Gu, and Kalki Seksaria. 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: IBM, Usenix, TwoSigma, and Jump Trading.

We hope to see everyone again soon for the March contest -- just one more contest to go before the U.S. Open!

Happy coding!

- Brian Dean (
Director, USA Computing Olympiad