National Olympiad in Informatics - Philippines (Practice Page)

Here are all the problems used for NOI.PH. Have fun!

Starts in


This is the archive of all past NOI.PH problems. Feel free to practice and submit anytime :)

To see the list of problems all at once, click here.

The National Olympiad in Informatics - Philippines is the Philippines' national qualifying round for the International Olympiad in Informatics, the most prestigious high-school level computer science competition in the world.

NOI.PH is offering a prize for every 5000 points from a single participant! After getting 5000 points, email us at so we can verify your submissions and you may receive your prize!


  • Please refrain from discussing strategy during the contest.
  • All submissions are run through a plagiarism detector. Any case of code plagiarism will disqualify both users from the contest.
  • You can also code using our interface, which currently supports over 40 major languages. Learn about our environment and time limits here. If you are not yet familiar with our platform, check out Solve Me First to acquaint yourself with I/O.
  • HackerRank admin decisions are final.


  • Each challenge has a pre-determined score.
  • Your score for a problem depends on the number of test cases your submission successfully passes.
  • A participant's total score is the sum of the scores earned for each problem attempted. If you submitted more than one solution for a problem, only your highest score achieved will be used in this calculation.
  • Participants are ranked by score, with the cumulative time taken (between the contest's start time and the time of your correct submission) used to break ties.

Not a genuine coding contest?