Welcome to Codebreaker!

Codebreaker is the official platform for Singapore Informatics Olympiad training and contests. We have run selection for the International Olympiad in Informatics for the delegations of Singapore and Indonesia, as well as countless official national and school training programmes.

1567 problems

All problems

464000 submissions

Recent submissions

4243 users

Rankings

Public Contests
Traffic (CloudFlare)

Submissions Per Day
Most Attempted Problems (Past Week)
Problem Users
helloworld 16
gcd 16
rightangtri 13
3nplus1 11
prefixsums 10

Most Submitted Problems (Past Week)
Problem Submissions
add1_easy 73
gcd 59
rabbitbars 58
catlunch 53
votingcities 51