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Indian Computing Olympiad | Registration

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Participating in the Indian Computing Olympiad (ICO) is like a dream come true for many budding computing or programming enthusiasts. The ICO is hosted by the Indian Association for Research in Computer Science and is a nationwide event. This competition allows talented school students to exhibit their programming or logical skills in a national event. The ICO is observed by computing enthusiasts and companies all across the country, ensuring that skilled students get all the exposure that they deserve.

Fundamentally, the Indian Computing Olympiad is orchestrated for selecting four of the most skilled students in computing for representing India during the IOI event or the International Olympiad for Informatics. IOI is the Computer Science counterpart of the other International Science Olympiads such as the ones focused on Mathematics, Biology, Chemistry or Physics. TCS or Tata Consultancy Services is an official partner of ICO as they conduct the Zonal Informatics Olympiad or ZIO, the preliminary round of the ICO. Alongside TCS, CodeChef’s platform is also used to conduct the ZCO or Zonal Computing Olympiad (another alternative preliminary exam).

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Eligibility Criteria

Firstly, the student must be studying in an Indian school, however, students from any board such as CBSE, ICSE, IGCSE or State Boards can apply. Applicants can be from any grade up till class 12 unless they have already given their 12th and they are planning to retake their board examinations. Once you pass your 12th grade examinations, you are not eligible to apply even if you are taking a break and not enrolled in college.

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Exam Pattern

The ICO has been segregated into two rounds in order to efficiently allow the most skilled students to be selected to represent India during IOI events. Let’s check what these rounds are.

The first round: Students can choose to take the ZIO or ZCO as the first round to progress into the main round of the ICO. ZIO is a written examination that is conducted across the country with the help of TCS and is generally held during November or December. ZCO is the other alternative, which is a programming examination that is also held across the country during the same time (November or December). ZCO allows candidates to use programming languages of their choice such as Python, Java, C++ and C.

Regardless of students choosing to take the ZIO or ZCO examination, if they are successful then they will proceed to the next round, which is the Indian National Olympiad in Informatics (INOI). However, due to some recent changes, Python, Java and C will not be available for students to use and they can only use C++.

The second round: As we discussed, the second round is the INOI, which is completely programming-based. It is more advanced than ZCO and is challenging for even the smartest of students. The INOI syllabus is much more vast and incorporates various new concepts, thus, requiring much more preparation than the ZIO or ZCO. This round is generally conducted during the end of January or February. About thirty students are selected from INOI in order to be trained in the IOITC or IOI Training Camp so that the final team can be selected to represent India in the IOI. The IOITC is held online and starts from the month of March or April, being held till about June.

Previous Asked Questions

Here are some more question papers for the last 10 years of ZIO examinations:

And here are some examples of past ZCO problems such as the Variation problem from 2015 and the Substring Importance problem from 2018. You can also choose to check out the Weird Ordering problem or the Four Sum problem.

As an example, here is the algorithm for the Weird Ordering Problem:

order(arr, i) {
   if length(arr) <= 1 {
     return arr
   l = []  
   r = []
   n = length(arr) - 1
   for j in 0, 1, ..., n {
      if ( (arr[j] modulo power(2,i+1))  < power(2,i) ) {
         append arr[j] to l
         append arr[j] to r
   l = order(l, i + 1)
   r = order(r, i + 1)
   c = concatenate(l, r)
   return c

You can also choose to practise some more advanced and beginner-level coding problems for the main INOI examination or even the future IOI exam through Coding Ninjas Coding Ninjas Studio. 

Here are some example problems:


The only prerequisites of the ICO are as follows:

  • The student must have not completed class 12th and must be studying in an Indian school, regardless of the board.
  • The applicant must have completed ZCO or ZIO and successfully finished the INOI.
  • Candidates must be proficient in C++ as IOI has removed Java as an official language. Thus, students can only use C++ during IOI.
  • Students must have successfully completed IOITC.

How to Register?

It has been decided that the ZIO-2022 will be taking place on 5th December 2021. However, the details for the ZCO-2022 are still to be finalised. Registration for the ICO-2020 will be opening up by the October 15th, 2021. For more details, you can check this official IARCS document for updates. For any doubts and confusion, you can also go ahead and write an email to Mr Madhavan Mukund, the National Coordinator for the ICO at

Preparation Tips

Here are some preparation tips for the ICO:

Frequently Asked Questions

How do I apply for the Indian Computing Olympiad?

You can apply for the ICO from October 15 onwards by going to the IARCS website or by registering for ZCO or ZIO through partners such as TCS and CodeChef.

How can I participate in IOI from India?

You can participate in IOI from India by first clearing INOI and successfully getting selected from the IOITC finalists.

How do I join IOI?

You can participate in the IOI after completing IOI training, which will be available for 30 students.

How do I apply for the Zonal Informatics Olympiad?

You can apply for the ZIO through TCS’s portal once registration starts.

Can I use Python in IOI?

No, you can only use C++ in IOI now. Python and Java were allowed before but are not official languages of the IOI anymore.

What is the ICT Olympiad?

The ICT Olympiad stands for the Information and Communications Technology Olympiad.

Should I give both the ZCO and ZIO?

No, it is only necessary to clear any one of the two.

What is the IOITC?

IOITC is a training session for the IOI that takes place from March till about June to train around 30 students and then finally select the most skilled out of them to represent India in the IOI.

What is the INOI?

INOI stands for Indian National Olympiad for Informatics and is the second round that students must clear after finishing the ZCO or ZIO.


The IOI-2022 will be taking place in Indonesia and will provide ample opportunities in the form of scholarships, grants and direct admissions to participants. So, why wait? Start preparing for the Indian Computing Olympiad 2022 and represent your country in the highly acclaimed IOI. Dozens of universities across the globe offer admissions and scholarships to IOI medallists and participants, thus, ensuring them a great future ahead.

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