• The creator of this contest is solely responsible for setting and communicating the eligibility requirements associated with prizes awarded to participants, as well as for procurement and distribution of all prizes. The contest creator holds HackerRank harmless from and against any and all claims, losses, damages, costs, awards, settlements, orders, or fines.
• Code directly from our platform, which supports over 30 languages. Learn more here.

Problem Solution

• A problem solution is a program written in one of the following programming languages (different problems can be solved in different programming languages, the list of languages can be widened):
  1. С/С++
  2. Delphi/Pascal
  3. Java
  4. С#
  5. Python
  6. Ruby
  7. PHP
  8. OCaml
  9. Haskell
  10. Perl
  11. Scala
  12. D
  13. Go
• Requirements to the solutions:
  1. The full program should be contained in a single file.
  2. If the problem statement doesn't specify the names of input or output, you must read the data from the standard input and write it to the standard output.
  3. You are forbidden to work with the Net.
  4. You are forbidden to perform input-output operations except for opening, closing, reading and writing files and standard streams given in the problem statements to perform input-output.
  5. You are forbidden to run other programs and create processes.
  6. You are forbidden to modify files or directories' permissions in the file system.
  7. You are forbidden to work with directories other than the current one.
  8. You are forbidden to work with the operating system registry.
  9. You are forbidden to create and use GUI elements (windows, dialogs etc.)
  10. You are forbidden to work with external devices.
  11. You are forbidden to perform any other actions that can in any manner destabilize the judging process.
• After a contestant solves a problem, he submits the solution via the contest system interface and continues working on other problems. After the system receives and judges a solution, it immediately responses by displaying the result of judging the solution.
• A contestant can see the results of judging of his solutions on the corresponding tab of the contest system. During a contest a contestant can see the results of only his solutions' judging.

Compiling solutions

• As a contestant submits a solution, he chooses a compiler that the judging system should use as it compiles the program. The judging system uses the following compilers for judging (the jury has the right to add other compilers at its discretion or replace the compiler's versions with the newer ones):
  1. MinGW GNU C++ 4
  2. MinGW GNU C 4
  3. MS VS C++ 2010
  4. Free Pascal 2
  5. Delphi 7
  6. C# Mono 2
  7. Java 6, 7
  8. Ruby 1
  9. Python 2
  10. PHP 5
  11. Haskell GHC 6
  12. Objective Caml 3
  13. Scala 2
  14. Perl 5
  15. MS C# .NET 4
• The contest organizers are not responsible for problems caused by the compiler's version in the judging system not matching the compiler's version used by the contestant as he was writing the program. To partially avoid such problems, there is an option to run a contestant's code on the server's side. To run the code, the contestant should submit the program and the input to the server. After a while the judging system will display the result of the program's execution and the output.
• Solutions are compiled and run under Windows OS. Line breaks are set by a couple of symbols #13#10. A file's or an input's last line should end with a line break (right before the end of the file).
• If a compilation error occurs, than the contestant gets the judging result as 'Compilation error' and the compilation log.
• The size of the file with the source code shouldn't exceed 64 kilobytes.

Judging Solutions

• During the contest the solutions are judged on a small number of tests called pretests.
• The result of judging the solution on the pretests are displayed to the contestant right after the judging.
• Each test is represented by the input for the contestant's program. The limits for the input contained in the test are indicated in the problem statement.
• All problems indicate the maximum time a program can take to work on one test and the maximum memory that can be consumed.
• Judging is performed by consecutively running the program on each test.
• The test is considered passed if running the program terminated with the return code 0, the process fit into the given time and memory limits and besides, the program printed the correct answer to the given test. The table below gives the most frequent verdicts of possible errors.

Can-do's and Can't-do's

• During the round the contestants are allowed to use any books and personal notes as well as a code written beforehand by you personally.
• It is forbidden to use somebody else's code in the solution. You may use third-party prewritten code with some restrictions, read carefully about it.
• It is allowed to use any sources of information on the Internet (but it is forbidden to copy-paste somebody else's code).
• It is forbidden to obfuscate the solution code as well as create obstacles for its reading and understanding. That is, it is forbidden to use any special techniques aimed at making the code difficult to read and understand the principle of its work.
• The contestants are forbidden to talk about subjects, related to the problems, with anybody, including other contestants. It is only allowed to ask questions to the jury via the system (see the 'Questions' section).
• The organizers of the contests have the right to monitor the contestants' honesty in behavior using different methods and disqualify the contestant if violations are found.
• All programs submitted by the contestants for judging, should be aimed at solving the problem and not at violating rules or destabilizing the judging system. A contestant who deliberately attempts to destabilize the judging system, will be disqualified.
• Attempting to digitally extract other contestant's code during the hacking is considered cheating. You may not use any technical/digital tools to obtain other contestant's code, including (but not limited) OCR, traffic capture, browsers plugins and so on. The only allowed method to analyze other contestant's solution is reading it in a hacking window. However it is allowed to manually retype the solution or it's parts to run it locally.
• Any violation of these rules, rules from the FAQ section, rules from the contest announcement or rules that were accepted during the registration will lead to penalty provisions, including disqualification.