JOI Open Contest 2013

JOI Open Contest 2013 was held on Sunday, June 23, 2013.

This is an IOI-like open competition for students at schools for secondary education. The main purpose of this contest is to give an opportunity to Japanese delegations and candidates of delegations for training and practice. But the contest itself is open to everybody. Everybody is welcome to attend JOI Open Contest 2013!

The duration of the contest is 5 hours. After the contest finishes, we will open the judging server for more than 24 hours. Interested contestants can improve and resubmit their solutions by themselves. Also, interested people living in different time zones will be able to enjoy the contest.

No registration is required: The contestants will be able to sign in the contest system using their Twitter or Facebook accounts.

After the contest, we will fix the standings. No prizes will be given to the contestants.

Contest Information

JOI Open Contest 2013
Contest System
CMS (customized; You can see the sources at here)
Contest duration
5 hours
The number of tasks
3 tasks
English, Japanese
Date & Time
Sunday, June 23, 2013
13:00-18:00 +0900 (JST)
04:00-09:00 (UTC/GMT)
Judging Server is open until
Monday, June 24, 2013
23:00 +0900 (JST)
14:00 (UTC/GMT)

Registration is not required. Please use your Twitter or Facebook accounts to sign in the contest system.


Rules that are same as IOI 2013 Rule:

Rules that are not same as IOI 2013 Rule:


Problem Statements