XNOR Algorithm Challenge

Starts in


XNOR is an Algorithm Development Challenge organized by the Royal College Computer Society in order to develop and sharpen the logical thinking abilities of Royalists.


  • First to answer correctly for each question will be awarded a valuable certificate.
  • Winners of previous competitions will be listed here


  • 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.
  • Participants must submit their own work. Plagiarism will lead to immediate disqualification.
  • Contestants may use the specified Languages to submit their solutions.


  • Each challenge has a pre-determined score.
  • A participant’s score depends on the number of test cases a participant’s code submission successfully passes.
  • If a participant submits more than one solution per challenge, then the participant’s score will reflect the highest score achieved. In a game challenge, the participant's score will reflect the last code submission.
  • Participants are ranked by score. If two or more participants achieve the same score, then the tie is broken by the total time taken to submit the last solution resulting in a higher score

Sign up for XNOR now.