Mobile Development



1. Terms

The competition is open to anyone over the age of 18. Employees of Yandex LLC or affiliated companies and their close relatives, as well as organizers, are excluded from participation in the competition. Participation is not open to persons who were employees of the Organizer and/or affiliates in the period from July 13, 2021 to October 31, 2021, other persons involved in the organization of the contest, as well as their family members.

2. Registration

You should register to participate in the competition. The Organizer reserves the right to disqualify a participant who has provided false information about himself/herself when registering. Registration will be opened on August 17, 2020 at 9:00 and will last until October 25, 2020 at 23:00 Moscow time (UTC+3).

Upon registration, a participant confirms that he/she is familiar and agrees with the Competition Regulations posted at and the Competition Rules posted at

3. Round assessment system:

Running the competition

The qualifying round is 120 minutes in duration and consists of 6 assignments, the final round is between 120 and 180 minutes in duration and consists of 6 assignments. The number of attempts to solve an assignment is restricted to 100 attempts per assignment. The assignments solved are submitted to be assessed during the competition. Participants send their assignments solved to the testing system using the software provided as soon as they are ready. When sending an assignment solved, the participant selects which compiler will be used by the testing system running under Linux. For information about compiler settings and configuration of testing servers, see the Сompiler Settings section.

Each assignment solved is assessed by system tests that are hidden from the participants and are the same for all participants. Testing runs automatically, so participants' assignments solved must adhere exactly to the input and output file formats described in the conditions of each assignment. Unless otherwise specifically stipulated, all input data to verify an assignment solved are assumed to be correct and meet all the restrictions specified in the conditions of the assignment.

Maximum time to complete a test and maximum amount of space used for each test are specified in the conditions of each assignment. If at least one of these limits is exceeded, the test is considered failed.

When the assignment solution is ready, the participant uploads it to the contest system for assessment and can carry on search for other assignments to be solved.
List of possible verdicts of the testing system


Has Test Number been sent?


Possible cause



The assignment solving is accepted

The program works correctly on the corresponding set of tests

Compilation error


Program compilation failed with an error

1. The program contains syntax or semantic error;
2. The language specified is incorrect

Wrong answer


The answer is incorrect

1. The program contains an error;
2. Invalid algorithm

Presentation error


Output data cannot be verified because their format does not match the format described in the conditions of the assignment.

1. Invalid output format;
2. The program does not print the result;
3. Redundant output

Time-limit exceeded


The program exceeded the stipulated time limit

1. The program contains an error;
2. Inefficient solution

Memory limit exceeded


The program exceeded the stipulated memory limit

1. The program contains an error (infinite recursion, for example);
2. Inefficient solution

Run-time error


The program ended with a non-zero return code

1. Run error;
2. Operator does not end Program in C or C++ with return 0;
3. Non-zero return code is specified explicitly

If the Compilation error occurs, , the assignment solution sent will not be assessed on any of the tests, and the participant will immediately be notified of the compilation error. This attempt will not be considered while the subsequent penalty is charged. If the Run-time error, Memory limit exceeded, and the Time-limit exceeded error occur, the program output is not verified.

Assignment solutions sent in a row with identical source code by the same participant are ignored.

Intermediate and final results' calculation

Participants are ranked by the number of points scored. Participants who have scored the same number of points are ranked by the total time spent for solving.

The time spent to solve an assignment is calculated in seconds beginning from the start of the competition until the time of sending the correct solution that has scored the largest number of points.

Assignments with no points scored by the end of the competition are not taken into consideration when calculating the total time.

The current results table reflects the number of points scored by a participant in an assignment. An assignment may include several groups of tests. A participant's solution scores points for a group of tests if he/she successfully passes all tests in the said group. A participant's solution may score between 1 and 5 points for each group of tests, and points scored for various groups of tests are summed up. The time spent by a participant to solve an assignment is considered to be the latest time since the start of the competition, when the participant bettered his/her scores.

The results table will be frozen one hour before the end of the competition. The decision on the winners will be taken after additional verification is made based on the results of the competition.

4. The Competition Structure

The qualifying round will start on October 19, 2020 at 12: 00 and end on October 25, 2020 at 23:59. Please note that you will have access to assignments during 120 minutes even if you started the round in the last five minutes before the end of the qualifying stage.

During this period, each registered participant can begin at a convenient time; the duration of the round will be 120 minutes. The start time is indicated in Moscow time (UTC+3).

The result of the qualifying stage includes two values: the number of points scored for assignments solved and the assignment solving time.

A participant is placed higher in the final table of the qualification stage if he/she has scored more points for assignments considering the time spent for solving (if several participants have scored the same number of points, the participant with the lower assignment solving time is placed higher).

The final round is open for participants, who have scored five (5) or more points in the qualifying round.

The organizer reserves the right to lower the qualifying threshold if the number of participants who have scored 5 or more points in the qualifying round is less than 500.

The final round of the competition will be held on November 7, 2020.

5. Prizes

Details of the Prizes are contained in the Competition Regulations:

Machine Learning