We're thrilled to invite you to participate in our upcoming CodeCombat Replay Round 2026 programming contest at SeriousOJ.

• Problem setter : Nasif_44th, Bullet, _ASRafi__

• Problem Tester : Ami_Nul, Toufik, _MJiH_, Muhammad_Nadim, Itsmdshahin

• Time: Friday, 17 April 2026 at 20:30 (BST)

• Problems: 10 (one problem divided into two subtasks)

• Duration: 2:30 hours

• Difficulty: Similar to Codeforces Div 3

• Rated : Level 0 — Level 10

Special thanks to CLown1331, owner of SeriousOJ.

Update 1 : Congratulations to the winners!

1. mikelou

2. SlyGaleeb

3. Hrkisback01221

4. OnsiteCurse

5. mindflux

Update 2 : Editorial

This round was originally conducted as an onsite contest, and now we are bringing it to a wider global audience. If you have already participated in the onsite round, we strongly recommend that you refrain from participating in this contest.

Registration: Please register for the contest on SeriousOJ. If you encounter any issues on the register, be sure to check your spam folder for the confirmation email.

Good luck & Have fun!!!

We're thrilled to invite you to participate in our upcoming Happy New Year 2026 programming contest at SeriousOJ.

• Problem setter : thakuremon, Bullet, _ASRafi__, Abid_52

• Time: Tuesday, 6 January 2026 at 20:30 (BST)

• Problems: 7

• Duration: 2:30 hours

• Difficulty: Similar to Codeforces Div 3

• Rated : Level 0 — Level 10

Special thanks to CLown1331, owner of SeriousOJ.

Update 1: Time extended by 15 minutes.

Update 2: Congrats to the winners!

1. physics0523

2. zanj0

3. hieptk

4. drydock

5. buko

Update 3 : Editorial

Registration: Please register for the contest on SeriousOJ. If you encounter any issues on the register, be sure to check your spam folder for the confirmation email.

Good luck & Have fun!!!

We're thrilled to invite you to participate in our upcoming Educational Round 1 programming contest at SeriousOJ.

• Problem setter : thakuremon, Bullet, _ASRafi__, Abid_52, _MJiH_

• Time: Monday, 14 July 2025 at 20:30 (BST)

• Problems: 5(one problem divided into two subtasks)

• Duration: 2:15 hours

• Difficulty: Similar to Codeforces Div 3

• Rated : Level 0 — Level 10

Special thanks to CLown1331, owner of SeriousOJ.

Update1 : Congrats to the winners!

1. Egor

2. physics0523

3. shogo314

4. nickbelov

5. norxondor_gorgonax

Update 2 : Editorial

Registration: Please register for the contest on SeriousOJ. If you encounter any issues on the register, be sure to check your spam folder for the confirmation email.

Good luck & Have fun!!!

We're thrilled to invite you to participate in our upcoming Brain Booster Round #10 programming contest at SeriousOJ.

• Problem setter : Nasif_44th, thakuremon, Bullet, _ASRafi__, Abid_52

• Time: Friday, 13 June 2025 at 20:30 (BST)

• Problems: 6-8

• Duration: 2:15 hours

• Difficulty: Similar to Codeforces Div 3

Special thanks to CLown1331, owner of SeriousOJ.

Registration: Please register for the contest on SeriousOJ. If you encounter any issues on the register, be sure to check your spam folder for the confirmation email.

Good luck & Have fun!!!

We're thrilled to invite you to participate in our upcoming Brain Booster Round #9 programming contest at SeriousOJ.

• Problem setter : thakuremon, Bullet, _MJiH_ , _ASRafi__, Abid_52

• Time: Sunday, 6 April 2025 at 20:30 (BST)

• Problems: 8

• Duration: 2:15 hours

• Difficulty: Similar to Codeforces Div 3

Special thanks to CLown1331, owner of SeriousOJ.

Update : Congrats to the winners!

1. __baozii__

2. cjoa

3. marksman_

4. Not_So_Great

5. Ami_Nul

Registration: Please register for the contest on SeriousOJ. If you encounter any issues on the register, be sure to check your spam folder for the confirmation email.

Good luck & Have fun!!

We're thrilled to invite you to participate in our upcoming Brain Booster Round #8 programming contest at SeriousOJ.

Details:

• Problem setter :Nasif_44th, cloud_007, thakuremon, Bullet, _MJiH_

• Time: Monday, 17 February 2025 at 20:30 (BST)

• Problems: 7 (one problem will have subtasks)

• Duration: 2:15 hours

• Difficulty: Similar to Codeforces Div 3

Special thanks to CLown1331, owner of SeriousOJ.

Update : Congrats to the winners!

1. dssfsuper2

2. ajinkya1p3

3. __baozii__

4. AlveRahman

5. sahaun

Soon, we will publish all problem editorial on our website.

Registration: Please register for the contest on SeriousOJ. If you encounter any issues on the register, be sure to check your spam folder for the confirmation email.

Good luck & Have fun!

We're thrilled to invite you to participate in our upcoming Happy New Year 2K25 programming contest at SeriousOJ.

Details:

• Problem setter :Nasif_44th, cloud_007, thakuremon, Bullet, _MJiH_

• Time: Thursday, 2 January 2025 at 20:30 (BST)

• Problems: 8

• Duration: 2:15 hours

• Difficulty: Similar to Codeforces Div 2 / Div 3

Special thanks to CLown1331, owner of SeriousOJ.

Registration: Please register for the contest on SeriousOJ. If you encounter any issues on the register, be sure to check your spam folder for the confirmation email.

Good luck & Have fun!

We're thrilled to invite you to participate in our upcoming LU IUJPC : Sylhet Division 2024 Replay programming contest at SeriousOJ.

Details:

• Problem setter : CLown1331, AlveRahman, cloud_007, thakuremon, Bullet, _MJiH_

• Tester : UshanGhosh, SajidZakaria, ammelid, Nasif_44th, _ASRafi__, Abid_52

• A heartfelt thanks to _Ash__ for his valuable feedback on some of the problems.

• Time: Tuesday, 10 December 2024 at 15:00 (BST)

• Problems: 11

• Duration: 5 hours

• Difficulty: Similar to Codeforces Div 2

Special thanks to CLown1331, owner of SeriousOJ.

Update : Editorial

Registration: Please register for the contest on SeriousOJ. If you encounter any issues on the register, be sure to check your spam folder for the confirmation email.

Good luck & Have fun!

We're thrilled to invite you to participate in our upcoming Brain Booster #7 programming contest at SeriousOJ.

Details:

• Problem setter : Bullet, thakuremon, _MJiH_, cloud_007

• Time: Tuesday, 5 November 2024 at 20:30 (BST)

• Problems: 8

• Duration: 2:15 hours

• Difficulty: Similar to Codeforces Div 2 / Div 3

Special thanks to CLown1331, owner of SeriousOJ.

Registration: Please register for the contest on SeriousOJ. If you encounter any issues on the register, be sure to check your spam folder for the confirmation email.

Update : Congrats to the winners!

1. Egor

2. AlveRahman

3. outlander

4. shelby70

5. sahaun

Good luck & Have fun!

We're thrilled to invite you to participate in our upcoming Brain Booster #6 programming contest at SeriousOJ.

Details:

• Problem setter : Bullet, thakuremon, _MJiH_

• Time: Thursday, 3 October 2024 at 20:30 (BST)

• Problems: 8 (one problem will have subtasks)

• Duration: 2:15 hours

• Difficulty: Similar to Codeforces Div 3

Special thanks to CLown1331, owner of SeriousOJ.

Registration: Please register for the contest on SeriousOJ. If you encounter any issues on the register, be sure to check your spam folder for the confirmation email.

Good luck & Have fun!

Update: Congrats to the winners!

1. alexwice

2. sahaun

3. penguin133

4. flying_saucer

5. SajidAbdullah

Hello Codeforces community,

We're excited to officially introduce SeriousOJ, our new online judge platform. While we've already hosted a few contests, we're thrilled to invite you to participate in our upcoming Brain Booster #5 programming contest.

Details:

• Problem setter : Bullet, thakuremon, _MJiH_

• Time: Thursday, 5 September 2024 at 20:30 (BST)

• Problems: 7 (one problem will have subtasks)

• Duration: 2:15 hours

• Difficulty: Similar to Codeforces Div 3

Special thanks to CLown1331, owner of SeriousOJ.

Registration: Please register for the contest on SeriousOJ. If you encounter any issues on register, be sure to check your spam folder for confirmation email.

Good luck & Have fun!