USACO December 2013 Contest -- Final Results

The USACO December 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 1912 participants submitted at least one solution, hailing from 73 different countries:

  812 USA  219 CHN  131 VNM   58 BLR   57 IRN   55 CAN   37 GEO
   31 MEX   27 MNG   27 DEU   24 RUS   23 KOR   23 ARM   21 KAZ
   20 IND   18 ROU   17 AUS   16 BRA   15 AZE   14 VEN   14 TUR
   14 BGR   13 LTU   12 TKM   12 SRB   12 HRV   12 FRA   11 THA
   11 POL   11 BGD   10 IDN    9 MKD    8 CUB    7 TWN    7 JPN
    7 ITA    7 GRC    6 ZAF    6 TJK    6 SGP    6 DOM    5 UKR
    5 LVA    4 EST    4 EGY    3 SYR    3 SVN    3 PER    3 NZL
    3 NLD    3 GBR    3 CZE    3 ARG    2 ISR    2 FIN    2 AUT
    1 VAT    1 TUN    1 SVK    1 PRT    1 MNE    1 MDA    1 ISL
    1 HKG    1 GIB    1 GHA    1 ESP    1 CYP    1 COL    1 BIH
    1 BEL    1 ASM    1 ABW

The average participant submitted solutions for 2.2 problems. In total, there were 4272 graded submissions, broken down by language as follows:

 2393 C++           
 1143 Java          
  469 Pascal        
  102 Python 2.7.2  
   83 C             
   82 Python 3.2    

Gold Division Results

Full Gold Results

The Gold division had 248 total participants, of whom 172 were pre-college students.

Congrats to the following 11 pre-college participants with perfect scores!

Country   Grad   Name Score
VNM  2014    Nguyễn Quang Dũng1000
USA  2014    Jerry Ma1000
CHN  2014    Mingda Qiao1000
CHN  2014    Lemon Xu1000
USA  2014    Bill Cooperman1000
ROU  2014    Andrei Heidelbacher1000
SRB  2015    Marko Stankovic1000
AUS  2015    Michael Chen1000
CHN  2015    Xu Yinzhan1000
USA  2015    Scott Wu1000
USA  2016    Demi Guo1000

Top observers in the gold division were:

Country   Name Score
JPNUwi Tenpen1000
VNMLe Minh Hoang Hnue1000
ZAFBruce Merry1000
ARMAlbert Sahakyan1000
RUSGerald Agapov1000
RUSAlexey Safronov833
BGDNazmul Hasan833
RUSDmitry Gorbunov833
USACalvin Deng800
RUSNikolay Kuznetsov800

Silver Division Results

Full Silver Results

The Silver division had 373 total participants, of whom 297 were pre-college students.

We had quite a few perfect scores among our pre-college participants -- 17 of them! Congratulations to the following individuals:

Country   Grad   Name Score
CHN  2015    Exia Cai1000
USA  2015    Luke Liao1000
IRN  2014    Reza Soltani1000
GHA  2015    Xuanyuan Luo1000
THA  2016    Theemathas Chirananthavat1000
TWN  2015    Brian Chen1000
BRA  2014    Mateus Bezrutchka1000
HRV  2014    Mislav Bradac1000
POL  2014    Michał Wiatrowski1000
POL  2015    Marek Zbysiński1000
SGP  2014    Ranald Lam1000
RUS  2014    Aidar Sayranov1000
BLR  2015    Alex Vistyazh1000
KOR  2016    Seunghyun Joe1000
HRV  2016    Domagoj Bradac1000
THA  2014    Krittisak Chaiyakul1000
THA  2015    Phoomraphee Luenam1000

Top observers in the silver division were:

Country   Name Score
CHNDaniel Duan1000
ZAFShaylan Lalloo1000
DEUFelix Bauckholt1000
VNMVan Hanh Pham1000
NLDMathijs van de Nes1000
USABob Suffern873
FINMatias Lahti867
CHNYisong Wang833
VNMHoàng Phú Nguyễn833
KORSeunghyun Jo833
BLRIlya 833

All participants with scores at least 800 will be automatically promoted to the gold division for future contests.

Bronze Division Results

Full Bronze Results

The Bronze division had 1291 total participants, of whom 1008 were pre-college students.

There were also quite a few perfect scores among the bronze pre-college participants:

Country   Grad   Name Score
SYR  2014    Alex Abbas1000
BLR  2014    Nikita Samsonov1000
ZAF  2014    Robin Visser1000
USA  2017    Ariadne Liu1000
IRN  2015    Mamad Esi1000
CHN  2014    Yang Tianlong1000
CHN  2015    宇 陈1000
IRN  2015    Navid Rahimidanesh1000
VNM  2015    Thang Tran1000
CHN  2015    Xiaotian Le1000
USA  2015    Guy Blanc1000
USA  2015    Elizabeth Wei1000
USA  2014    Daniel Johnson1000
USA  2014    Nima RD1000
USA  2015    Daniel Ju1000
AUS  2016    Declan McDonnell1000
USA  2015    Zhixin Feng1000
CHN  2015    Yufei Wang1000
VNM  2015    NhaDinh Cao1000
USA  2015    Francis Gerard1000
USA  2016    Theodore Katz1000
ROU  2016    Mihail Jianu1000
RUS  2014    Nikita Podguzov1000
TUR  2016    Yunus Emre Inci1000
DEU  2016    Viktor Yuschuk1000
POL  2016    Tomek Kościuszko1000
CHN  2014    Wenzhang Cheng1000
USA  2015    Jonathan Roche1000
CHN  2015    Xinjian Yu1000
IRN  2015    Ali Haghani1000

Top observers in the bronze division included:

Country   Name Score
CHNBin Li1000
NZLRyan Smith1000
CHNChu Wei1000
SRBDragan Markovic1000
FRAAlexis Comte1000
CANTed Ying1000
RUSIgor Pyshkin1000
BGDMohammad Samiul Islam1000
ARMNarek Hovsepyan1000
VNMLoc Duc933
CANMartin Mika933

All participants with scores at least 800 will be automatically promoted to the silver division for future contests.

Final Remarks

Another successful contest! Score distributions in all three divisions look quite reasonable, with many participants earning reasonable amounts of points, but only a small handful achieving perfect or nearly-perfect scores. Promotion cutoffs were a bit more strict with this contest, requiring bronze and silver students to make good progress on all three problems in order to earn promotion.

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, Kalki Seksaria, Fatih Gelgi, Bruce Merry, Travis Hance, and Richard Peng. 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 look forward to seeing everyone again in early 2014 for our January contest.

Happy coding!

- Brian Dean (
Director, USA Computing Olympiad