USACO November 2013 Contest -- Final Results

The USACO November 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 2612 participants submitted at least one solution, hailing from 79 different countries:

 1139 USA  290 CHN  121 VNM   77 IRN   65 IDN   60 CAN   54 BLR
   52 TUR   46 GEO   39 MEX   38 KAZ   31 KOR   30 ROU   29 IND
   29 BGR   29 ARM   26 BRA   25 VEN   25 MNG   25 DEU   24 EGY
   21 THA   19 RUS   17 HRV   16 FRA   15 UKR   15 POL   14 TKM
   13 BGD   12 AZE   12 AUS   11 TJK   11 CUB   10 SGP   10 LVA
   10 LTU    9 JPN    8 SRB    8 ITA    8 GRC    7 SYR    7 MKD
    7 ISR    6 ZAF    6 GBR    6 DOM    5 TWN    5 PRT    5 NLD
    5 KGZ    5 CYP    4 SVK    4 MYS    4 FIN    4 EST    4 CZE
    3 HKG    3 AUT    2 SVN    2 MNE    2 MDA    2 COL    2 BIH
    2 ARG    1 WLF    1 VGB    1 VAT    1 SAU    1 PAK    1 NZL
    1 NGA    1 LUX    1 LKA    1 ISL    1 GHA    1 ESP    1 CHL
    1 BEL    1 ASM

The average participant submitted solutions for 1.9 problems. In total, there were 4986 graded submissions, broken down by language as follows:

 2900 C++           
 1359 Java          
  378 Pascal        
  136 Python 2.7.2  
  124 C             
   89 Python 3.2    

Gold Division Results

Full Gold Results

The Gold division had 244 total participants, of whom 128 were pre-college students. Congrats especially to the five pre-college competitors with perfect scores: Ray Li, Bill Cooperman, Yechan Bae, Steven Hao, and Scott Wu! The top pre-college gold scores were:

Country   Grad   Name Score
AUS  2014    Ray Li1000
USA  2014    Bill Cooperman1000
KOR  2014    Yechan Bae1000
USA  2014    Steven Hao1000
USA  2015    Scott Wu1000
EST  2014    Oliver-Matis Lill879
CZE  2014    Martin Raszyk879
AUT  2015    Gary Ye818
ROU  2014    Andrei Heidelbacher818
IDN  2014    Stefano Chiesa818
SRB  2015    Marko Stankovic818
BLR  2014    Dima Demidko818
VNM  2014    Xuan Hung Cao818
CHN  2015    Yuetong Wang818
KAZ  2015    Zhusupov Nurlan818
BLR  2014    Vadim Zakharenko818
USA  2016    Lawrence Li818

In the observer category, there were eleven participants with perfect scores:

Country   Name Score
ZAFBruce Merry1000
USALewin Gan1000
USARay Li1000
JPNUwi Tenpen1000
DEUAlexander Rass1000
IDNAhmad Zaky1000
USACalvin Deng1000
RUSEgor Kulikov1000
DOMCarlos Toribio1000
KORGyeongGeun Kim1000
DEUHans S1000

Silver Division Results

Full Silver Results

The Silver division had 317 total participants, of whom 230 were pre-college students. In general, scores were quite good in the silver division, with 13 perfect scores in the pre-college category:

Country   Grad   Name Score
RUS  2014    Nikita Uvarov1000
VNM  2015    Khanh Do Ngoc1000
BLR  2016    Ilya Medyanikov1000
IDN  2014    Muhammad Rais Fathin Mudzakir1000
ROU  2014    Tudor Tiplea1000
VNM  2014    Viet Do Xuan1000
CHN  2014    Zecong Hu1000
TUR  2015    Abdullah Enes Oncu1000
USA  2016    Jordan Alexander1000
ROU  2014    Radu Visan1000
ROU  2016    Vlad Tarniceru1000
SVN  2014    Patrik Zajec1000
KAZ  2014    Zhanadil Nurtoleuov1000

Top scores among the observers were:

Country   Name Score
DEUFlorin-Cristian Ghesu1000
CHNZhou Zhou1000
KAZYerzhan Utkelbayev1000
IRNMehrdad Miri1000
NZLTom Levy1000
VNMMinh Duc Bach970
IDNAmmar Fathin Sabili970
CHNJinglun Li970
SGPWeiLiang Gan939
CANAngus Kong939

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

Bronze Division Results

Full Bronze Results

The Bronze division had a record 2051 total participants, of whom 1532 were pre-college students. As is often the case on the first contest of the year, we had a large number of perfect scores in both the pre-college category:

Country   Grad   Name Score
SGP  2014    Ranald Lam1000
IRN  2017    Amirmohammad Dehghan1000
AUS  2014    Daaron Chiu1000
POL  2014    Michał Wiatrowski1000
USA  2014    Michael LoPiccolo1000
SGP  2017    Wen Yuen Pang1000
IRN  2014    Reza Soltani1000
CHN  2014    Yukun Ma1000
AZE  2014    Tahir Alizade1000
RUS  2014    Aidar Sayranov1000
USA  2015    Philip Sun1000
USA  2018    William Hu1000
USA  2015    Stanley Xie1000
VNM  2014    Tri Nguyen1000
USA  2017    Nicholas Guo1000
THA  2016    Theemathas Chirananthavat1000
RUS  2014    Emil Guseynov1000
EGY  2014    Mahmoud Aladdin1000
CHN  2016    Jingtao Liang1000
HKG  2015    Alex Tung1000
BLR  2014    Andrew Ilyin1000
HRV  2014    Mislav Bradac1000
USA  2015    Eric Neyman1000
DEU  2014    Paul Gölz1000
THA  2015    Phoomraphee Luenam1000
USA  2014    Alan Jaffe1000
CAN  2015    Ben Zhang1000
USA  2014    Beilin Li1000
ISL  2017    Jack Helgosen1000
POL  2014    Jakub Staroń1000
AUS  2014    Oliver Fisher1000
HRV  2015    Kristijan Vukelić1000
IRN  2016    Farbod Yadegarian1000

and also in the observer category:

Country   Name Score
CHNJiancheng Liu1000
CHNPhoenix Wright1000
USAJason Fieldman1000
CHNDaniel Duan1000
NLDTom Bannink1000
RUSIgor Kraskevich1000
USAZaphod Beeblebrox1000
USAAlexey Alexandrov1000
CHNYanYi Liu1000
NLDAbe Wits1000
IDNIvan Koswara1000
JPNIkumi Hide1000
INDSaurabh Modi1000
SYRHussain Kara Fallah1000
ARGMartin Arjovsky1000
AUSJames Payor1000
CHNShuo Han1000
CHNDavid Feng1000
CHNQi He1000
CHNYangzhuo Lin1000
TWNLuffy Hsu1000
THAPichayut Liamthong1000
USAShane Albright1000
SVKRastislav Rabatin1000
CHNShuxin Chen1000
BRABianca Oe1000
CHNYisong Wang1000
CHNLiu Tao1000

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

Final Remarks

In terms of numbers, this was by the far the largest USACO contest ever held to date, with more than 2600 participants worldwide. I am very happy to see our numbers increasing at a rapid pace! I was also quite happy with the overall score distributions; many students turned in very impressive results on this challenging contest, and have earned promotion 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 in the world, and it can take a good deal of genuine practice to excel at them. For our newer students, note that everyone at the top of the gold division now started out not long ago exactly where you are, and I challenge all of you to continue to advance your programming and problem-solving skills until you also reach the top of the gold division one day.

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". I have also tried, as an experiment, posting video solutions of myself coding solutions to the bronze problems; hopefully these will provide more useful intuition and feedback to our newer competitors, and I'd welcome comments on how to make these even more effective.

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, Rumen Hristov, and Bruce Merry. 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 for the 2013 December contest.

Happy coding!

- Brian Dean (
Director, USA Computing Olympiad