USACO December 2012 Contest -- Final Results

The USACO December 2012 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 1424 participants submitted at least one solution, hailing from 75 different countries:

589 USA  87 CHN  73 VNM  57 CAN  48 IRN  35 BLR  28 IND
 27 MEX  24 KAZ  20 GEO  18 VEN  18 RUS  18 DEU  18 ARM
 16 ROU  16 IDN  15 SRB  15 BGR  14 TUR  14 KOR  14 BGD
 13 UKR  12 MYS  12 AUS  11 POL  11 HRV  11 CUB  10 TKM
 10 BRA   9 ITA   9 GRC   9 FRA   8 TJK   6 ZAF   6 TWN
  6 MKD   6 EGY   5 SVK   5 SGP   5 LVA   5 LTU   5 JPN
  5 HKG   4 ISR   4 DOM   4 CZE   4 AZE   3 YUG   3 THA
  3 MNE   3 GBR   3 EST   3 AUT   3 ARG   2 SWE   2 PRT
  2 MDA   2 BIH   1 SYR   1 RSA   1 PRK   1 PER   1 PAK
  2 NLD   1 LUX   1 KGZ   1 ISL   1 INA   1 HUN   1 GER
  1 ESP   1 CYP   1 COL   1 BUL   1 BEL

The average participant submitted solutions for 2.2 problems. In total, there were 3150 graded submissions, broken down by language as follows:

1853 C++
 866 Java
 264 Pascal
  91 Python
  74 C

Gold Division Results

The Gold division had 140 total participants, of whom 105 were pre-college students.

Full Gold Results

A number of gold competitors turned in impressive scores, including 4 perfect scores in the pre-college category and 7 in the observer category. Congratulations to these remarkable individuals! Top scores in the pre-college division are:

Country   Grad   Name Score
RUS  2013    Dmitry Gorbunov1000
USA  2015    Scott Wu1000
BLR  2013    Vlad Podtelkin1000
USA  2014    Steven Hao1000
BLR  2013    Constantine Sokol972
AUS  2015    Michael Chen900
VNM  2013    Nhat Tran861
CHN  2013    Lei Xu861
USA  2013    Daniel Ziegler833
VNM  2013    Bao Nguyen Le833
USA  2013    Calvin Deng833

and the top observers are:

Country   Name Score
EGYAhmed Salem1000
RUSMikhail Mayorov1000
BGRYordan Chaparov1000
RUSEgor Kulikov1000
DEUFabian Gundlach1000
ZAFBruce Merry1000
POLAdam Karczmarz1000
KAZAli-Amir Aldan794
CANJacob Plachta733
HUNBalazs Kezes700

Silver Division Results

The silver division had 418 total participants, of whom 335 were pre-college students.

Full Silver Results

Quite a few students scored very well in the silver division, including 8 perfect scores in the pre-college category and 5 in the observer category. Top students in the pre-college group are:

Country   Grad   Name Score
ROU  2014    Andrei Heidelbacher1000
BLR  2013    Pavel Sheftelevich1000
CHN  2013    Junru Shao1000
CHN  2014    Xianghao Tang1000
AUS  2015    Ishraq Huda1000
LVA  2016    Aleksejs Popovs1000
USA  2014    Dylan Cable1000
ITA  2013    Federico Glaudo1000
ISR  2013    Tom Kalvari967
USA  2013    Eugene Chen967

Top scores in the observer group are:

Country   Name Score
BGRAtanas Vulev1000
BRABruno Adami1000
RUSAlexander Agulenko1000
CHNJianjin Fan1000
BRAPaulo Cezar Pereira Costa1000
NLDJosse Dobben900
RUSPavel Kuznetsov833
CHNLi Zihao767
KORJeehak Yoon767
MYSRun Xian Tan733
CANJonathan Shen733
BGDMohammad Hafiz Uddin733
HRVBuda Budimir733
ROUMugurel Ionut Andreica733
ISLBjarki Agust Gudmundsson733
GBRRobin Lee733

All participants with scores at least 650 will be automatically promoted to the gold division for future contests.

Bronze Division Results

A total of 866 participants competed in the bronze division, 733 of them pre-college students.

Full Bronze Results

The bronze contest this time around proved to be quite challenging, with only a handful of very high scores. There were 10 perfect scores in the pre-college division:

Country   Grad   Name Score
RUS  2014    Nikolay Kalinin1000
RUS  2014    Petr Smirnov1000
PER  2014    Carlos Guillen1000
RUS  2014    Truong Nam Nguyen Huy1000
RUS  2013    Ivan Belonogov1000
TWN  2013    Robert Huang1000
CHN  2017    Weiqiang Yuan1000
POL  2016    Jaroslaw Kwiecien1000
IDN  2014    Stefano Chiesa1000
VNM  2014    Anh Khoa Tran Phan1000

Top scores in the observer category are:

Country   Name Score
SVKMichal Anderle1000
CHNZhao Shengyu1000
CHNElement Yao900
USAJoe Thuemler900
VNMMinh Duc Bach867
TWNWu HaiTao867
VNMManh Quynh867
BGDSakib Hasan833
BRADouglas Santos700
CHNJun Chen700
VNMHieu Pham700

All participants with scores at least 750 will be automatically promoted to the silver division for future contests.

Final Remarks

This turned out to be a relatively challenging contest, particularly at the bronze level, although a number of silver and gold problems also proved to be quite difficult. I am happy to see though that despite this difficulty, we still have a reasonable number of promotions 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, Nathan Pinsker, Travis Hance, Bruce Merry, Johnny Ho, and Jonathan Paulson. 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 January contest!

Happy coding!

- Brian Dean (
Director, USA Computing Olympiad