November 2011 Contest -- Final Results
The USACO 2011 November Contest featured algorithmic programming problems covering a wide range of techniques and levels of difficulty. Click here to see the contest problems and solutions.
A total of 1450 participants competed in the contest -- a new record! We saw participants from 74 different countries:
566 USA 99 CHN 66 VNM 42 IRN 40 BLR 39 IDN 38 GEO 37 CAN 34 ROM
33 KAZ 31 MEX 28 TUR 23 RUS 22 BRA 21 ITA 20 TWN 16 KOR 16 HRV
14 ROU 14 LTU 14 DEU 14 BGR 13 MKD 13 GRC 13 EGY 12 IND 11 YUG
11 COL 11 AUS 10 TKM 9 POL 8 FRA 7 UKR 6 VEN 6 ARM 5 TJK
5 SRB 5 SGP 5 LVA 5 LKA 5 CUB 5 BGD 4 SVN 4 PER 3 THA
3 NZL 3 GBR 3 EST 3 DOM 2 ZAF 2 SYR 2 PRT 2 MNG 2 LUX
2 INA 2 HKG 2 DNK 2 AUT 2 ARG 1 TUV 1 SVK 1 NED 1 MDA
1 MAR 1 LBN 1 JPN 1 JAM 1 ISL 1 IRL 1 GER 1 FIN 1 CZE
1 CYP 1 ARE
The average participant submitted solutions for 2.6 problems. In total, there were 3878 graded submissions, broken down by language as follows (this was our first time ever supporting Python as a competition language):
2264 C++ 1041 Java 330 Pascal 173 C 70 Python
Gold Division Results
The Gold division had 167 total participants, of whom 98 were pre-college students.
A total of 13 pre-college students achieved perfect scores; congratulations on this superb achievement! The pre-college gold winners are:
| Country | Grad | Name | Country | Grad | Name |
|---|---|---|---|---|---|
| VNM | 2012 | Huy Tran | SYR | 2013 | Kinan Sarmini |
| ROM | 2013 | Gavrila Vlad | BLR | 2012 | Gennady Korotkevich |
| CHN | 2012 | Martin Token | BGR | 2012 | Rumen Hristov |
| BLR | 2012 | Adam Bardashevich | CHN | 2016 | Yuetong Wang |
| CHN | 2013 | LiJie Chen | CHN | 2012 | Wenhan Huang |
| USA | 2013 | Johnny Ho | IRN | 2013 | SeyedHamed Valizadeh |
| CHN | 2014 | Nanxin Chen |
Congratulations also to the 17 observers in the gold division with perfect scores:
| Country | Name | Country | Name | Country | Name |
|---|---|---|---|---|---|
| LVA | Eduard Kalinicenko | EGY | Hamza Ibrahim | CHN | Zechao Shang |
| KAZ | Ali-Amir Aldan | BLR | Aleksey Ropan | VNM | NguyenTS Nguyen |
| CHN | Qu Peng | IRN | Saeed Ilchi | ROM | Paul-Dan Baltescu |
| DEU | Daniel Kirch | ZAF | Bruce Merry | CHN | Neal Zane |
| DEU | Thomas Fersch | UKR | Yaroslav Tverdokhlib | CAN | Tyson Andre |
| DEU | Alexander Rass | CHN | Kuan Yang |
Silver Division Results
The silver division saw 200 total participants, of whom 166 were pre-college students.
The three problems in this division required clever algorithmic thinking and proved challenging for most of the competitors. Although there were many high scores, only three participants (all three of them pre-college students) turned in perfect scores:
| Country | Grad | Name |
|---|---|---|
| USA | 2014 | Steven Hao |
| USA | 2013 | Calvin Deng |
| CHN | 2013 | Grace Tsai |
Congratulations on achieving a perfect score on this very difficult contest! All three of you are promoted to the gold division for future contests. Promotion to gold is also available if desired for any participant receiving a perfect score on two of the three problems -- please email [email protected] if you fit into this category and wish to participate in the gold contest in December.
Bronze Division Results
A total of 1083 participants competed in the bronze division, 829 of them pre-college students.
Congratulations to the 79 pre-college students and 38 observers with perfect scores! All of you have been promoted to the silver division for future contests. The pre-college bronze winners are:
| Country | Grad | Name | Country | Grad | Name |
|---|---|---|---|---|---|
| RUS | 2013 | Alexander Mokin | CHN | 2014 | Chen Jianing |
| RUS | 2013 | Danil Medvedev | USA | 2013 | Davis Wang |
| VNM | 2013 | Dat Duong | LTU | 2013 | Vladimir Daglis |
| LTU | 2013 | Edgaras Liberis | USA | 2013 | Albert Chu |
| GEO | 2016 | George Skhirtladze | ROU | 2016 | Paul Gramatovici |
| USA | 2013 | Derek Lou | ROM | 2014 | Olariu Ciprian |
| FRA | 2012 | Simon Mauras | USA | 2013 | Sunny Nahar |
| CHN | 2013 | Xiang Wu | DEU | 2012 | Julian Labeit |
| TWN | 2013 | Jhih Bang Hsieh | TWN | 2012 | Shao-Chuan Lee |
| USA | 2013 | Jeffrey Yan | KAZ | 2013 | Eldar Aimakov |
| USA | 2012 | Scott DellaTorre | VNM | 2013 | ThnhAn Hng |
| USA | 2013 | Cody Silverman | MEX | 2014 | Daniel Talamas |
| USA | 2013 | Yimo Chen | VNM | 2012 | Bao Chiem Duy |
| MEX | 2013 | Edgar Augusto Santiago Nieves | AUS | 2014 | Ray Li |
| VNM | 2013 | Linh Ta | USA | 2014 | Jakob Weisblat |
| VNM | 2012 | Thanh Nguyen | BRA | 2013 | Kahn Slap |
| BRA | 2014 | Igor Wolff Resplande | CHN | 2013 | Peter Lee |
| LKA | 2012 | Hirantha Subasinghe | RUS | 2013 | Kirill Borozdin |
| ROM | 2012 | Cristian Lambru | RUS | 2013 | Vladimir Polushin |
| VNM | 2013 | Tuán Anh Nguyen | RUS | 2012 | Oleg Ivanov |
| USA | 2013 | Bo Moon | MKD | 2015 | Vasil Kuzevski |
| CAN | 2014 | Stella Lau | UKR | 2012 | Valentin Lukyanets |
| IRN | 2013 | Sobhan Miryoosefi | PER | 2012 | Dennis Huillca |
| RUS | 2012 | Gerald Agapov | USA | 2013 | Allan Sadun |
| VNM | 2012 | Shin Doyle | MEX | 2013 | Freddy Roman |
| USA | 2014 | Abhay Goel | IDN | 2013 | Jonathan Irvin Gunawan |
| HRV | 2014 | Martin Gluhak | ISL | 2012 | Bjarki Agust Gudmundsson |
| RUS | 2012 | Egor Suvorov | RUS | 2012 | Petr Mayorov |
| CAN | 2013 | Mehwar Raza | TUR | 2012 | Mustafa Erdogan |
| VNM | 2013 | Life Keeper | KAZ | 2012 | Ilya Dronov |
| KAZ | 2012 | Dias Abdraimov | SRB | 2014 | Ivan Stosic |
| IRN | 2013 | Daniyal Mehrjerdi | INA | 2012 | Setiadi Alvin |
| ITA | 2013 | Davide Pallotti | ITA | 2013 | Andrea Battistello |
| IDN | 2013 | Pusaka Kaleb Setyabudi | ITA | 2013 | Matteo Almanza |
| AUT | 2012 | Markus Hasenohrl | TUR | 2012 | Safa Andac |
| IDN | 2013 | M Aji Muharrom | CAN | 2014 | Henry Wu |
| VNM | 2013 | Bao Nguyen Le | USA | 2015 | Andrew He |
| IDN | 2013 | Vincent The | INA | 2012 | Amanda Pratama |
| IDN | 2012 | Jennifer Santoso | ITA | 2012 | Gabriele Farina |
| ITA | 2013 | Daniele Del Giudice |
The bronze observers with perfect scores are:
| Country | Name | Country | Name | Country | Name |
|---|---|---|---|---|---|
| IRN | Hooman Hashemi | MDA | Luncasu Victor | CAN | Robert Xiao |
| CHN | Baoer Yu | VNM | QViet Ky | VNM | Hoang Le |
| CHN | Shijian Liu | IRN | Shahriar Heshmat | CUB | Ernesto Carvajal |
| CHN | Yuwen Li | IDN | David Christopher | AUS | Andrew Haigh |
| KOR | GyeongGeun Kim | ARG | Federico Pousa | USA | Cheng Pan |
| DNK | Gert Hansen | CAN | Alex Velazquez | CHN | Guodong Feng |
| CHN | Lei Huang | ROM | Andrei - | GBR | Sean Quah |
| CHN | Derrick Chou | FRA | Zamato Lassts | PER | Johann Cortez |
| RUS | Mikhail Mayorov | GBR | Robin Lee | CHN | Tianyu Lou |
| COL | Alejandro Alejandro | ROM | Laurentiu Cristian Ion | SGP | Mark Theng |
| DEU | Florin-Cristian Ghesu | CHN | Han Zhu | BRA | Leonardo Conegundes |
| KOR | Myungwoo Chun | CHN | W Jn | TWN | How Jing |
Final Remarks
I'm quite happy with the overall results in each division -- the distribution of scores indicates that the problems were indeed quite challenging, but hopefully not to a point of being frustratingly difficult. If you are new to the USACO, you now have a good sense what to expect in terms of difficulty from our contests.
This contest was the first to run on our brand new web infrastructure; we are continuing to add features and improvements, so the next contest should have all the features you are used to with past USACO contests, including real-time feedback during the contest on whether your program answers the sample input correctly, the ability to view previous submissions, analysis mode after the contest ends, the ability to run your program on the grading server with your own input for timing purposes, and more. I appreciate everyone bearing with us during the migration, and I appreciate all the feedback you have given me to help improve the system for the next contest.
I am glad that cheating seemed to be at a minimum during this contest, and I hope it stays this way. I did unfortunately have to remove several participants for cheating on the contest (mostly by using multiple accounts during the contest -- don't do this!). Cheating is never really to your advantage, and it will result in your being banned from all future USACO contests. Also, please use your actual name in your account; although I respect the refined sense of humor of participants such as "Gangster Veggies" and "Fuzzy Fuzzy", I will generally remove entries from the final results until they come from accounts with legitimate names.
Thanks are due to a number of folks for their help getting this contest off the ground. The USACO coaching staff -- Neal Wu, Nathan Pinsker, Mark Gordon, Richard Peng, Albert Gu, Jacob Steinhardt, and Ben Cousins, were instrumental in helping with solutions and test data. Thanks to Rob Kolstad for helping with the website transition, and to Chad Waters for his help with the new back-end grading system. Excellent problems were contributed by Ray Li and Rob Seay (if you have good ideas for problems, please send them my way -- we are always looking for high-quality problems!). Thanks to the folks at Clemson CCIT, who have provided our new server. Finally, a huge round of thanks are due to our sponsors, whose support is absolutely crucial and much appreciated: IBM, Usenix, TwoSigma, and Jump Trading.
Thanks, and I hope to see all of you again in the December contest!
- Brian Dean ([email protected])
Director, USA Computing Olympiad