Name	CF Handle	Country	Birth Date	Previous IOIs
Sparik Hayrapetyan	sparik	Armenia
Eduard Grigoryan	edogrigqv2	Armenia		2010 2011 2013
Tigran Galstyan	Tiko	Armenia
Mushegh Shahinyan	MyLeg	Armenia
Florian Leimgruber	fleimgruber	Austria	07 Jun 1997 (16)
Gary Ye	GaryYe	Austria	15 Feb 1997 (17)	2013
Bristy Sikder	bristy1588	Bangladesh		2011 2012 2013
Labib Md. Rashid	Labib666	Bangladesh		2013
Tonmoy Mollik	triploblastic	Bangladesh
Hasib Al Muhaimin	hasib	Bangladesh	27 Oct 1996 (17)	2013
Аlexey Vistyazh	netman	Belarus
Dmitriy Demidko	dimad	Belarus	01 May 1997 (17)
Barbara Kuskova	kuskova	Belarus	29 Apr 1998 (16)
Fedor Korobeinikov	Mediocrity	Belarus	15 Feb 2000 (14)
Mauricio Wilde Monasterios	Daydreamer	Bolivia	01 Jul 1995 (18)	2013
Isabella Defilippis	Isa_Def	Bolivia
Ronaldo Franco	rony	Bolivia
Moises Vela	MoiTheKiller	Bolivia
Michel Zelazny	michelzel	Brazil		2013
Arthur Nascimento	arthur.nascimento	Brazil
Mateus Bezrutchka	m_bezrutchka	Brazil
Arthur Pratti Dadalto		Brazil
Hristo Venev	mustrumr	Bulgaria		2012 2013
Momchil Peychev	momo_vn	Bulgaria		2013
Encho Mishinev	Enchom	Bulgaria		2013
Stefan Ivanov		Bulgaria
Ben Zhang		Canada	29 Aug 1997 (16)
Yu Dingli	Leoyu	China
Xu Yinzhan	xyz111	China
Shen Yang	sy2006	China
Dong Honghua	dhh1995	China
Michalis Psalios	michael10024	Cyprus		2012 2013
Angelos Pelecanos	AnPelec	Cyprus		2013
Adamos Ttofari	adamos2468	Cyprus
Andreas Theocharous		Cyprus
Martin Raszyk	m.raszyk	Czech Republic		2013
Jan-Sebastian Fabík	fabik	Czech Republic
Ondřej Hübsch	ondrah	Czech Republic		2012
Dominik Smrž		Czech Republic
Yousef Ibrahim Salama	Yousef_Salama	Egypt		2012 2013
Ahmed Morsy	Ahmed_Morsy	Egypt	21 Nov 1995 (18)
Oliver-Matis Lill	oml1111	Estonia	28 May 1995 (19)	2013
Sami Kalliomäki	Scintillo	Finland		2012 2013
Henrik Lievonen	Hennkka	Finland		2013
Kalle Luopajärvi	kllp	Finland		2013
Petteri Timonen	P.T	Finland
Lucas Pesenti	md5_84	France	30 Mar 1997 (17)
Tomas Rigaux	Akulen	France	04 Nov 1997 (16)
David Cheikhi	cheikdav	France
Arthur Léonard		France
Nikoloz Svanidze	svanidz1	Georgia	01 Apr 1996 (18)	2012 2013
Elene Machaidze	emachaidze	Georgia	27 Sep 1997 (16)
Nika Nadiradze	nikanick11	Georgia	05 Mar 1996 (18)	2011 2012
Georgy Skhirtladze	gskhirtladze	Georgia	03 Aug 1999 (14)
Georgios Christoglou	Giorgos_Christoglou	Greece		2013
Aristofanis Rontogiannis	mentalist	Greece
Dimitrios Los		Greece		2012 2013
Georgios Venizelos	geroveni	Greece
Lau Ting Fung	master_miu	Hong Kong
Lik Hang Poon	hohomu	Hong Kong		2013
Kam Chuen Tung	alex20030190	Hong Kong		2013
Wai Pan Yik	jasonyik	Hong Kong		2012
Akshat Boobna	akshatb	India	06 May 1996 (18)	2013
Bhupesh Kumar	bhup99	India	10 Oct 1994 (19)
Nihal Pednekar	nihalpi1	India	26 Oct 1996 (17)	2013
Malvika Raj Joshi	a0666	India
Muhammad Rais Fathin Mudzakir	rais.fathin38	Indonesia
Stefano Chiesa Suryanto	zeulb	Indonesia		2013
Alfonsus Raditya Arsadjaja	radit	Indonesia
Zamil Majdy	kadalijo	Indonesia
Mojtaba FayazBakhsh	moji	Iran
Mohammad Amin Khashkhashi Moghaddam	alex-mercer	Iran
Amirmohsen Ahanchi	persianpars	Iran
Iliad Ramezani	Beranabus	Iran
Hirotaka Isa	HIR180	Japan	12 Apr 1998 (16)
Ken Ogura	catupper	Japan
Ryoma Sato	joisino	Japan	28 Jul 1996 (17)
Yuta Takaya	yutaka1999	Japan
Nurlan Zhussupov	Sick_coder	Kazakhstan		2013
Miras Myrzakerey	Miras321	Kazakhstan
Ulugbek Adilbekov	Algiz	Kazakhstan
Daniyar Maminov	LeMieux	Kazakhstan
Ruslan Rakhimov	ruslan.rakhimov	Kyrgyzstan	25 Oct 1997 (16)
Kadyrbek Narmamatov		Kyrgyzstan	24 Jan 1998 (16)
Aleksejs Zajakins	Alex_2oo8	Latvia		2013
Ingus Jānis Pretkalniņš		Latvia
Aleksejs Popovs	popoffka	Latvia		2011 2012 2013
Kristaps Čivkulis	how_to_become_purple	Latvia
Jordan Fernando Alexander Salas	HappyPerson	Mexico
Daniel Talamas Cano	allthecode	Mexico		2013
Diego Alonso Roque Montoya	Diego9627	Mexico		2013
Carlos Galeana Hernández		Mexico
Petar Djerkovic		Montenegro
Dejan Todorovic	dejo	Montenegro	28 Apr 1996 (18)
Petar Milosavljevic	ZipperMan	Montenegro
Grover Enrique Castro Guzman	vermen	Peru	17 Jan 1992 (22)
Michał Glapa	glapul	Poland	01 Oct 1995 (18)
Albert Citko	asterius	Poland
João Rocha	joaorocha619	Portugal
Pedro Amaro	mys	Portugal
Gonçalo Paredes	gonP	Portugal
Andrei Heidelbacher	andreihh	Romania	26 Aug 1995 (18)	2013
Rareș Darius Buhai	rares.buhai	Romania	18 May 1996 (18)	2012 2013
Alexandru Velea	alex.velea	Romania
Mihai-Dan Gheorghe	gheorghemihai	Romania		2011
Nikolay Kalinin	KAN	Russia		2013
Konstantin Semenov	zemen	Russia		2013
Nikita Uvarov	-imc-	Russia
Nikita Sivukhin	sivukhin	Russia
Ivan Stošić	ivan100sic	Serbia	04 Sep 1995 (18)	2012 2013
Dimitrije Erdeljan	dd__	Serbia	23 Apr 1997 (17)	2013
Marko Stanković	MeinKraft	Serbia	15 Jun 1996 (17)	2013
Andrej Ivašković	Dreian95	Serbia	02 Apr 1995 (19)	2012
Feng Jiahai		Singapore
Mark Theng Kwang Hui		Singapore		2013
Xinyu Wu		Singapore
Ranald Lam Yun Shao		Singapore		2012 2013
Bui Truc Lam		Slovakia
Mário Lipovský		Slovakia
Michal Korbela	kabell	Slovakia
Eduard Batmendijn	Baklazan	Slovakia	19 Jan 1996 (18)	2012 2013
Seokhwan Choi	gs12117	South Korea	22 Dec 1996 (17)	2013
Jeehak Yoon	HYPERHYPERHYPERCUBELOVER	South Korea	10 Feb 1998 (16)
Johan Sannemo	jsannemo	Sweden		2012 2013
Hussain Kara Falah	Pepe.Chess	Syria	14 Dec 1997 (16)
Hasan Jaddouh	kingofnumbers	Syria
Aleksandar Abas	Alex7	Syria	13 Sep 1996 (17)
Joud Zouzou	RedNextCentury	Syria
Brian Chen	betaveros	Taiwan
Yi Zhou	qazwsxedcrfvtg14	Taiwan	03 Sep 1997 (16)
Pochang Chen	johnchen902	Taiwan	05 Nov 1997 (16)
Tzu Peng Wang	paulwang	Taiwan	19 Sep 1996 (17)
Kai-Chieh Chang	ihave33cm	Taiwan 2	25 Mar 1997 (17)
Abduqodiri Qurbonzoda	abdukodir	Tajikistan		2012 2013
Dzhamshed Khaitov	Jamik	Tajikistan		2012 2013
Mekhrubon Turaev	Ximera	Tajikistan		2013
Doro Umarov	Alnair	Tajikistan		2013
Phoomraphee Luenam	Phoom	Thailand
Pichayut Liamthong	pichayut	Thailand		2013
Krittisak Chaiyakul	toppykung	Thailand		2013
Semih Basrık	sbasrik	Turkey		2013
Muhammed Emin Ayar	EMINAYAR	Turkey	01 Aug 1997 (16)
Halil Ozan Akgül	halilozanakgul	Turkey	19 Jun 1996 (17)
Abdullah Enes Öncü	enesoncu	Turkey
Bayram Berdiyev	bayram	Turkmenistan
Bayram Guvanjov	bayram98	Turkmenistan
Sylap Aliyev	accidentallygivenfuck	Turkmenistan	11 Nov 1997 (16)	2013
Andriy Omelyanenko	Omelianenko	Ukraine	04 May 1997 (17)
Ilya Shevchenko	Scorpy	Ukraine		2013
Misha Babenko	NegaTeeF	Ukraine
Andrej Selivanov	seland	Ukraine
Scott Wu	scott_wu	United States		2012 2013
Andrew He	ecnerwala	United States
Steven Hao	stevenkplus	United States		2013
Joshua Brakensiek	AstroConjecture	United States		2013
Kien Nguyen	kien_coi_1997	Vietnam	30 Nov 1997 (16)
Phuc Ngo	nhap96	Vietnam
Viet Do	Aquacloud	Vietnam
Dung Nguyen	ig_dug	Vietnam

UPD 1 Please feel free to post the participants here too, so that there will be something to discuss :)
UPD 2 Now you can see IOI stats profile page of a participant :)
UPD 3 Congratulations! to those who qualified for IOI 2014 :)

I remember that I saw Barcelona 2014 Contest by Petr in CF Gym while taking a look at contests list in clist.by.
Does anyone know where is that contest now?

A. Camel Caravan

There is a caravan of n camels. You are fed up with seeing the same camel day after day. Now you wonder, how many ways are there to reorganize the camels, so that no camel sees the same camel as before?

По пустыне идет караван из n верблюдов. За много дней путешествия надоедает идеть впереди себя одного и того же верблюда. Сколькими способами можно переставить верблюдов так, чтобы впереди каждого шел другой верблюд, чем до этого?

B. Magic is Might

Given natural number k. Find k^th number in the sequence consisting of powers of 2: 2481632...
For example for k = 4 answer is 1.

Задано некоторое натуральное число k. В последовательности 2481632... составленная из степеней 2 найти цифру стояшей на k - ом месте.
Например для k = 4 ответ 1.

C. Tom Marvolo Riddle

Given n natural numbers. Find smallest natural number, which can not be represented as sum of given numbers, if in the representation one number can be used only once.

Даны n натуральных чисел. Найти минимальное натуральное число, непредставимое суммой никаких из этих чисел, если в сумму каждое исходное число может входить не более одного раза.

D. Fractions

Given natural number n. Find all irreducible regular fractions where i is in range [1, n - 1].

Дано натуральное число n. Найти все несокротимые правильные дроби, знаменатель которых равен n, а числитель принимaет значения, находящиеся в диапазоне [1...n - 1].

Time & Memory Limits

You can find details here.

Natural numbers

I hate problem statements where term "natural number" is used. You can't know if zero is included or not. And when I asked if zero is included or not in TKMNOI, I recieved "10th grade and you don't know that?!", when the whole world doesn't know that.

Note 1: As you may have noticed I couldn't come up with good task names, because these tasks don't deserve good names :D
Note 2: Feel free to leave comments about tasks and their solutions.

Day1 Tasks

A. Bet you can't solve it

You need to build a stairway, which has 1.5 unit height and 4.5 unit width. Each step has to have 0.3 unit height and multiple of 0.5 unit width. How many different ways are there to build such a stairway?

Строится лестница из точки А в точку В. Растояние АС = 4.5м; ВС = 1.5м. Высота ступеньки 0.3м, ширина 0.5м или кратное 0.5м. Сколькими способами можно построить лестницу?

Sample stairway. Original images for description.

B. Piece of cake

Given matrix A[1...n][1...m], each element of which is 0, 1, 2 or 3. Find number of 4-ples A[i][j], A[i][j + 1], A[i + 1][j], A[i + 1][j + 1] where these numbers differ from each other.

Данна целочисленная матрица А[1...n][1...m],каждый элемент которой равен 0, 1, 2 или 3.Определить количество четвёрок A[i][j], A[i][j + 1], A[i + 1][j], A[i + 1][j + 1] в котором все элементы различны.

C. Strange Problem

Continue the sequence of 3-digit numbers: 215, 717, 316, 512 ...

Продолжить последовательность трёхзначных чисел: 215, 717, 316, 512 ...

D. Knights' Invasion

Find a way to place 12 knights so that every cell is either attacked or is owned by a knight.

Найти такую расстановку двенадцати коней на шахматной доске, при котором каждое поле будет находиться под ударом одного из них.

Day2 tasks are available here.

Constraints

Participant: What is the limit for N?
Jury Member: N can be anything... The limit for it is infinity...
Participant: But no computer can handle infinity? :D
Jury Member: That is your problem! You should try to solve it for infinity.

But actual tests are the ones that can be calculated by hand.

Time limit

Depends on the patience of the juries. Usually around 10 minutes.

Memory limit

Free memory available in the PC given to you.

Note1 Original blog title was «Turkmenistan National Olympiad in Informatics sucks». And it really does.
Note2 Actually tasks had no names. I gave the names.
Note3 Feel free to give your answers for A,C,D.

Does anyone know how to run CMS in Ubuntu >=12.04?

I need sample session where it shows everything from installing CMS (although I know how to), configuring it correctly (CMS itself, PostgreSQL, ... which I find really confusing) to running a test contest.

I started following instuctions from CMS documentation, but now I am lost.
I know almost nothing about listening to a port, PostgreSQL,...

Hi all,
I've been trying to solve this problem at TOJ.
I am recieving TLE for following simple code (I just scan input):

#include <iostream>
#include <algorithm>
using namespace std;

int m, n, res;
int b[500];
int r[500];

int main()
{
	while (true) {
		cin >> m;
		cin >> n;
		
		if (m == 0 && n == 0)
			break;
		
		for (int i = 0; i < m; i++)
			cin >> b[i];
		
		for (int i = 0; i < n; i++)
			cin >> r[i];
	}
	
	return 0;
}

If any of you is familiar with (have been solving problems for long time) TOJ, please tell me what is wrong.

This Saturday we have Topcoder SRM 600. Lets discuss problems here or here. :)

Good luck!

P.S. Strange that there is no blog about this SRM from Omelianenko. :D

UPD: T-shirt winners :|

Today I decided to practice in Topcoder Practice Rooms for the first time. And I opened Topcoder Arena. What I first felt is a big dissappointment about its interface. It was so ugly, it reminded me gaming communities such as RGC,... I want to know what you feel about TC Arena's UI. Maybe someone can request TC admins to change their UI. :(

EDIT: I take my words back. Web Arena is cool!

Today I realized that I cannot implement GCD segment tree with range update & range query, the same way I did for min/max/sum segtree with range update & range query. Now I wonder is it possible to write this kind of segment tree with O(logN) complexity for each operation? Operations:

• Add some number x to range [l, r]
• Find GCD of range [l, r]

P.S. not to be confused with:

• Initialize each number in range [l, r] to x
• Find GCD of range [l, r]

Hi all,

Currently I'm trying to write simple online judge. I'm having troubles in manipulating processes, detecting TLE, MLE, ... Maybe you can help me in some way, maybe by providing link to some open source online judge, or answering me here.

Thanks in advance.

EDIT : I mistyped the title Wri**n**ting Online Judge in PHP. I can't believe that I didn't notice :)

Today while searching for CEOI 2012 Results, I spotted this, and I wanna share it with you :) ...

“Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning.” Rich Cook.

“The perfect computer has been developed. You just feed in your problems and they never come out again.” Al Goodman.

“If the automobile had followed the same development cycle as the computer, a Rolls-Royce would today cost $100, get a million miles per gallon, and explode once a year, killing everyone inside.” Robert X. Cringely.

“If debugging is the process of removing bugs, then programming must be the process of putting them in.”

“There are 10 types of people in the world: those who understand binary, and those who don’t.”

“My software never has bugs. It just develops random features.”

“Programmers are tools for converting caffeine into code.”

“If at first you don’t succeed; call it version 1.0″

Hi,
Some of you may know that in January 12-18 International Zhautykov Olympiad will be held. I heard that in contest environment, there is only CodeBlocks available. Is it really true?

If YES can you please reply asap, so that I can get familiar with CodeBlocks beforehand.

If NO which editors are (or will be) available this year?

Screenshot from 09/21/2013 03:13AM	Screenshot from 09/26/2013 08:51AM

Maybe somebody hacked Codeforces and DROPPED/EMPTIED some TABLE :)

Problem link : 340E - Iahub and Permutations
Can anyone prove following:

dp[i] = (y+i-1)*dp[i-1] + (i-1)*dp[i-2];

This is an AC solution by problem-solved : 4384292

Hi everybody. Does anybody know a way how to test your program in Linux. I know how to do it in Windows 7.

For example (file gr.bat) ::

copy <input_file_name_in_test_data>.in.%1 <input_file_name_default>.in
<executable_file_name>
fc <output_file_name_in_test_data>.out.%1 <output_file_name_default>.out

(you can set the syntax yourself)

to test just enter in cmd gr 1 , gr 2 , ... or gr x for test x.

Thanx in advance.

UPD: LOTS OF THANKS to razimantv and Xerxes. [SOLVED]

A few hours ago i was surfing the WWW and saw codeforces article at wikipedia. And the article is in danger of extinction. Please edit the article and help to keep honor of codeforces. Here is a link.