Thanks for participating in the DMOPC this month! Congrats again to the top 5 contestants:

1. ecnerwal
2. ksun48
3. cool_serena
4. tabr
5. Egor

Happy holidays, and see you next year!

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We're back! We know everyone is exhausted during this final stretch before the holidays, so we prepared another contest to cheer you up!

The contest will run from Friday, December 17th to Monday, December 20th (inclusive of both days).

Anyone with a DMOJ account is welcome to participate, and anyone without one is welcome to register and participate.

Contestants may participate in any 3-hour window between 00:00:00 EST of December 17th and 00:00:00 EST of December 21st. Please see the contest page for more details.

GLHF!! <3

Welcome to the WOSS Dual Olympiad 2021: Computer Science Individual Round!

The Junior Contest will have a difficulty range from CCC Junior 1 to CCC Junior 4

The Senior Contest will have a difficulty range from CCC Senior 1 to CCC Senior 3

The contest will be from December 14, 2021, 3:00 PM EST to December 20, 2021, 11:59 PM EST

The contest is hosted by WOSS Mathematics Club and WOSS Computer Science Club.

Executives

• Tianyue Ruby Sun: TRS
• Pranav Vyas: bobthesnek63
• Jake Shin: jakeshin2004
• Manasva Katyal: SuperMK
• George Fan: Wozunubi
• Julia Xu
• Jacob Yan: Codester
• Oliver Mao
• Leo Bai

A special thank you to Riolku and maxcruickshanks for their help with contest organization and problem testing!

Thanks for participating!

The top 5 contestants are

1. xiaowuc1
2. SourSpinach (the second time they have placed in the top 5!)
3. skittles1412 (the second time they have placed in the top 5!)
4. goffrie
5. kevinyang

We hope to see you again in February!

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Hi, everyone again!

On Friday, December 17th, 2021, we'll be running the second SAC Code Challenge for this year!

You can write this year's contest in any two-hour window between December 17th, 00:00 EST, until December 21st, 00:00 EST. The contest will be composed of 5 problems with problem difficulty ranging from CCC Junior 1 to CCC Senior 3.

Additionally, the problems will be themed around Christmas.

Like the most recent Code Challenge, there will be no registration requirements to participate.

You can find more details on the contest page.

We hope to see you soon!
SAC Code Culture.

DMOJ is hosting an unofficial mirror of the NOIP '21 — the Chinese National Olympiad in Informatics Provincial Round (NOIP, approximately equivalent to CCC Stage 1).

The contest can be found here.

There are 4 problems, each worth 100 points, and the contest window is 3 hours long.

This contest will not be rated.

As always, thanks for participating in the DMOPC this month! Special congrats to the top 5 contestants:

1. ecnerwal (perfect score!)
2. Gennady
3. bruce
4. wleung_bvg
5. SkyCrystal

See you soon!

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Hello again! Winter is now approaching, but so is the third DMOJ Monthly Open Programming Contest of the season!

The contest will run from Saturday, November 13th to Tuesday, November 16th.

Anyone with a DMOJ account is welcome to participate, and anyone without one is welcome to register and participate.

Contestants may participate in any 3-hour window between 00:00:00 EST of November 13th and 00:00:00 EST of November 16th. Please see the contest page for more details.

See you soon!

Thanks for participating!

The top 5 contestants are

1. SourSpinach
2. Plasmatic
3. skittles1412
4. explosion
5. BalintR

We hope to see you again in December!

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Hi, everyone!

On Friday, October 29th, 2021, we'll be running the first annual and second-ever SAC Code Challenge!

You can write this year's contest in any two-hour window between October 29th, 00:00 EDT, until November 1st, 00:00 EDT. The contest will be composed of 5 problems with problem difficulty ranging from CCC Junior 1 to CCC Senior 3.

Additionally, the problems will be themed around Halloween.

Unlike last year, there will be no registration requirements to participate.

You can find more details on the contest page.

We hope to see you soon!
SAC Code Culture.

Thanks for participating this time! The top 5 contestants are:

1. ksun48
2. Gennady
3. wleung_bvg
4. SourSpinach
5. dalt

We'll be back again in November!

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Hello again! To celebrate Thanksgiving Day, we'll be hosting the second DMOJ Monthly Open Programming Contest of the season!

The contest will run from Saturday, October 9th to Tuesday, October 12th.

Anyone with a DMOJ account is welcome to participate, and anyone without one is welcome to register and participate.

Contestants may participate in any 3-hour window between 00:00:00 EDT of October 9th and 00:00:00 EDT of October 12th. Please see the contest page for more details.

See you soon!

In light of recent events, DMOJ administrators have decided to not process any support requests about account recovery, starting January 1st, 2022 (which is now in effect). If you lose your second authentication factor, you must use the recovery code generated when you enabled two-factor authentication (2FA). If you do not have a recovery code, access to your account will be lost forever. This is done purely for security reasons, to protect you from social engineering attacks.

Two-factor authentication is designed to protect an account even when the password (or equivalently, the email with which the user could reset it) is compromised. Therefore, a genuine recovery request is indistinguishable from the following attack:

Suppose you are Alice, and an attacker Mallory has somehow gained access to your email. Then, Mallory can send an email to the DMOJ admins, claiming that she is Alice, has lost her phone, and begs the admins to reset 2FA. Since the admins do not know either Alice or Mallory in real life, it is conceivable that an admin could be tricked into believing Mallory is really Alice and granting the request. Now, Mallory obtains access to the account Alice, even though 2FA is supposed to prevent her from doing so.

Therefore, the only option DMOJ admins have to safeguard your account security is to ignore all support requests about account recovery. Please keep your recovery codes safe. If you don't know them, you can go to the edit profile page, regenerate them, and store them in a safe place. Thank you.

Thanks to everyone for participating in this DMOPC, and special congrats to the top 5 contestants! They are:

1. zhouzixiang2004 (perfect score)
2. ecnerwal (perfect score)
3. Gennady
4. ksun48
5. hitonanode

We hope you enjoyed the contest, and we'll see you again next month!

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From Saturday, September 4th to Tuesday, September 7th, we'll be hosting the first DMOJ Monthly Open Programming Contest of the season!

Anyone with a DMOJ account is welcome to participate, and anyone without one is welcome to register and participate.

Contestants may participate in any 3-hour window between 00:00:00 EDT of September 4th and 00:00:00 EDT of September 7th. Please see the contest page for more details.

See you soon!

DMOJ is hosting An Unrated Contest, a fun contest running for a week. As the name suggests, it is unrated, though it contains normal problems. The problems are just not quite fit for a rated contest.

You can check out more details on the contest page.

Have fun!