Informatics Olympiads

What is Informatics olympiad?

The Informatics Olympiads are competitive programming contests for secondary school students. They require basic skills in algorithms and data structures.

In India we have the Indian Computing Olympiads which leads to the International Informatics Olympiad(IOI). The Indian Computing Olympiads are managed by IARCS (Indian Association for Research in Computing Science).

The first International Informatics Olympiad was held in 1989 in Pravetz, Bulgaria. It is one of the major science Olympiads besides Mathematics, Physics, Chemistry, Biology and Astronomy.

India started participating in the year 2002. Recently, Akshat Bubna got the first ever gold medal for India in 2014 (and also won the Go For Gold challenge by Codechef).

IOI 2015 will be conducted in Kazakhastan.

The process :

Stage 1 a: ZIO (Zonal Informatics Olympiad)

The ZIO is a written test in which the candidate will be given 4 or 5 mathematical questions to solve within 3 hours. For this level no knowledge in programming languages are required. One would need a good sense of logic and aptitude to pass this test.

Last year the centre in Assam was South Point High School.

Stage 1 b: ZCO (Zonal Computing Olympiad)

The ZCO is a programming test in which one would be given 2 problems to solve within 3 hours. This requires a basic knowledge of algorithms and programming languages to pass. It is conducted online.

Last year’s ZIO was held at Saturday, November 23 and ZCO was held at Saturday November 30. Around 7400 students wrote ZIO in 39 centres of which 282 qualified and about 100 appeared ZCO of which 30 qualifed. The dates for this year’s ZIO and ZCO will be announced very soon on the IARCS website.

Participants may go to Stage 2 by passing either 1a or 1b.

Stage 2: INOI (Indian National Olympiad in Informatics)

The INOI is a programming competition similar to ZCO except that fact that it is onsite. Participants will be given 2 problems to be solved in 3 hours for which they must submit a working code in C, C++, Java or Pascal. Around 25 participants get selected for the next round.

INOI 2014 was held at Saturday, January 18th.

Stage 3: IOITC (International Olympiad in Informatics Training Camp)

This is usually a 10-14 days camp which is held in Bengaluru. The selected 25 people are invited to the camp. Advanced algorithms and data structures will be taught and practice tests will be held. 3 final tests each containing 3 problems to be solved in 5 hours will be held at the end of the camp which would be used to select the team of 4 people to represent India at the International Olympiad of Informatics.

Stage 4: IOI (International Olympiad in Informatics)

This is the final stage where the selected team contests with the teams from other nations. There will be two days of competition in which each day will have 3 problems to be solved in 5 hours.

In IOI C, C++ and Pascal and occasionally FORTRAN and PHP,  C++11 starting from IOI 2014 are allowed, while Java is being planned to be added in IOI 2015. 50% of the students get medals in the ratio 1:2:3 for Gold:Silver:Bronze.

Each year it is held in a different country. This year it was held in Taiwan. Next year it will be held in Kazakhastan.

How to prepare :

One should practice previous years’ papers. One should study a lot of algorithms which are there in the links provided below. Only learning the algorithms is not sufficient. One should also be able to code it.

Some Books :

Introduction to Algorithms; T.H. Cormen, C.E. Leiserson, R. Rivest, C. Stein
Introduction to C++; R. Sedgewick
Art of Computer Programming; D. Knuth

Some useful links

IARCS website :
IARCS online training material :
Code chef:
Code forces:
IOI website :
Sphere Online Judge(SPOJ) :

Some more links are provided in the following two pages :

[This article is intended for awareness. It was written after a series of discussions between Bishal Deb, A. R. Balasubramanian and Goutham R., students of CMI. Both Goutham and Balasubramanian are qualifiers of INOI.]