Hello Codeforces!

We are hosting four live and exciting rated 15-minute 15-problem rounds, at 7 PM for the Under 1400 division, and then 7:30 PM, 8 PM, and 8:30 PM for everyone! (all ET) — This is a cool opportunity to compete with some really good mathletes!

You can Register Here for Lightning 4, 5, 6, and 7 (note: this will take you to Lightning 5, you can click on 'Contests' to register for the others! If your rating is 1400 or above, you will be unable to register for Lightning 4) and/or join the discussion in Discord — and then come back at the competition time for an exciting round!

Hope to see you there! (Pictured is Lightning Round 3 from a few days ago :) )

Hello! Wanted to share a new Math Trainer that we developed — that gives you quality problems (rated highly by other users) at the difficulty level and subject of your choice. Would love to hear thoughts!

https://mathdash.live/trainer

Feel free to join our community in Discord or email us ( [email protected] )!

Hello! We would love to invite you to MathDash Daily 9 today any time within the next $$$24$$$ hours!

You will be offered 9 or 10 problems to solve in 40 minutes. The level is Math from a Div 5 level all the way to Div 1 level. The round will be rated for ratings 1600 and below. There will be five different divisions: Iron, Bronze, Silver, Gold, and Platinum. Enter here. We ask that you do not discuss the problems until 24 hours from now (i.e. after the Contest ends) — but general discussion/suggestions are welcome and encouraged below!

Feel free to join our community in Discord or email us ( [email protected] )!

Hello! We would love to invite you to MathDash Daily 8 today any time within the next $$$24$$$ hours!

You will be offered 10 problems to solve in 40 minutes. The level is Math from a Div 5 level all the way to Div 1 level. The round will be rated for ratings 1600 and below. There will be five different divisions: Iron, Bronze, Silver, Gold, and Platinum. Enter here. We ask that you do not discuss the problems until 24 hours from now (i.e. after the Contest ends) — but general discussion/suggestions are welcome and encouraged below!

Feel free to join our community in Discord or email us ( [email protected] )!

Hello! We would love to invite you to MathDash Daily 7 today any time within the next $$$24$$$ hours!

You will be offered 18 problems to solve. The level is Math from a Div 4 level all the way to Div 1 level. The round will be rated for ratings 1400 and below. Enter here. We ask that you do not discuss the problems until 24 hours from now (i.e. after the Contest ends) — but general discussion/suggestions are welcome and encouraged below!

Feel free to join our community in Discord or email us ( [email protected] )!

Hello! One of MathDash's most common requests has been to accomodate people in other time zones. This is now possible — we would love to invite you to MathDash Daily 6 today any time within the next $$$24$$$ hours!

You will be offered 15 problems to solve. The level is Math from a Div 4 level all the way to Div 1 level. The round will be rated. Enter here. We ask that you do not discuss the problems until 24 hours from now (i.e. after the Contest ends) — but general discussion/suggestions are welcome and encouraged below!

Feel free to join our community in Discord or email us ( [email protected] )!

MathDash now has up-solving support! You can see all problems from past contests sorted and filtered by difficulty, and upsolve problems by clicking on them.

If you wish for guidance/help on a problem, there is a Discord channel link on the problem page where we have a community very willing to help :) — let's see who can solve the most problems!

https://mathdash.live/problems

Hello! Would like to invite you all to four contests this week :)

MathDash Round 10 — with Prizes! on Monday March 18 at 7:30 PM EST (4:30PM PST).

MathDash Round 11 — with Prizes! on Wednesday March 20 at 7:30 PM EST (4:30PM PST).

MathDash Mock MATHCOUNTS Sprint on Thursday March 21 at 7:30 PM EST (4:30PM PST).

MathDash Round 12 — with Prizes! on Friday March 22 at 7:30 PM EST (4:30PM PST).

For each of Contests 10, 11, and 12, You will be offered 10 problems to solve. The prize fund for each of the three rounds will be $120

The top three contestants of Gold/Plat will get $25 — $20 — $15 respectively.

The top two contestants of Silver will get $20 — $15 respectively.

The top contestants in Bronze and Iron will get $15 — $10 respectively.

We really enjoy putting on these rounds for you all. Would love to hear feedback and suggestions in Discord or via email ( [email protected] )!

Hello! Would like to invite you all to MathDash Mock MATHCOUNTS Sprint on Thursday March 14 at 8:30 PM EST (5:30PM PST).

You will be offered 30 problems to solve. The round will be rated. Register here.

We really enjoy putting on these rounds for you all. Would love to hear feedback and suggestions in Discord or via email ( [email protected] )!

Hello! Would like to invite you all to MathDash Round 9 — with Prizes! on Monday March 11 at 7:30 PM EST (4:30PM PST).

You will be offered 10 problems to solve. The prize fund for this round will be $120

The top three contestants of Gold/Plat will get $25 — $20 — $15 respectively.

The top two contestants of Silver will get $20 — $15 respectively.

The top contestants in Bronze and Iron will get $15 — $10 &mdash respectively.

We really enjoy putting on these rounds for you all. Would love to hear feedback and suggestions in Discord or via email ( [email protected] )!

The New MathDash Arena has opened up!

Join us in the second MathDash Arena Marathon here from now until Friday March 15 (ending at 7:30 EST) — the prize fund is $150 (in Amazon gift cards)

There will be two simultaneous tournaments running: Category 1: Quick Maths — Zetamac, Sum of Squares, Prime Factorization, Hard Arithmetic Category 2: Contest Math — Bronze and Silver

At the end of the week, the Top 8 participants by rating and the Top 8 participants by Gold (who didn't already qualify by rating) in each category, will advance to the Final Showdown

If you qualify for the final showdown for Contest Math, you will be ineligible for the Quick Maths final showdown.

A time will be chosen for the 32 total contestants to undergo a live final showdown (details TBD) — there will be an asynchronous option for those who cannot make it.

The top three in each category will win $35 — $25 — $15 each (via Amazon Gift Card). Also, the top 8th grader and top <=7th grader in both categories that didn't already win a prize will win a month of MathDash premium membership!

Good luck!

Hello! Would like to invite you all to our new daily series of contests — MathDash Daily Round 1 on Wednesday March 6 at 9PM EST (6PM PST).

You will be offered 10 problems to solve. We are also giving out a prize for each of these daily contests — $10 to the top ranked participant in grade 8 or under (or the equivalent in the country of the participant)

We're bringing you CodeForces for Math — would love to have you join us on this journey.

If you're excited for this round, please comment your favorite math topic :)

Hello! Would like to invite you all to MathDash Round 8 — with Prizes! on Tuesday March 5 at 7:30 PM EST (4:30PM PST).

You will be offered 10 problems to solve. The prize fund for this round will be $110

The top five contestants of Silver will get $25 — $20 — $20 — $20 — $15 respectively.

The top contestant in Bronze gets $10

Tiebreaks will be done first by number of submissions and then by time of last correct submission.

We were super happy to see all the participation in Contest 7, our largest contest ever! Congratulations to the winners :)

Silver (37 registrants!)

1. Anonymous (10/10, 0 incorrect submissions, in 14 minutes 47 seconds) — Prize: $119

2. Nathan (10/10, 0 incorrect submissions, in 18 minutes 20 seconds)

3. Not (10/10, 0 incorrect submissions, in 21 minutes 15 seconds)

Bronze (139 registrants!)

1. Naveen (10/10, 0 incorrect submissions, in 4 minutes 14 seconds) — Prize: $17

2. Coby (10/10, 0 incorrect submissions, in 6 minutes 2 seconds)

3. Dilhan (10/10, 0 incorrect submissions, in 7 minutes 40 seconds)

Total prize fund ended up being $136

We really enjoy putting on these rounds for you all. Would love to hear feedback and suggestions in Discord or via email ( [email protected] )!

Also, we will have some exciting updates for you later in the week :) — stay tuned!!

Hello Codeforces!

My team has been running MathDash (Codeforces for Math) for a few weeks now, and are introducing

MathDash Round 7 with Cash Prizes! on Tuesday Feb 27 at 7:00 PM EST (4PM PST). Register using this link!

Prizes

Bronze: Winner gets $$$10 + \frac{x}{100}$$$ dollars

Silver: Winner gets $$$25 + \frac{x + y}{100}$$$ dollars

where $$$x$$$ is the total number of problems for which answers were submitted (correct or incorrect!) across all contestants in the Bronze division, and $$$y$$$ is the same for the Silver division.

In MathDash contest 6, this would have made the total prize pool **~80 dollars** — and this can increase significantly with more participation — if there are 100 participants in Bronze and Silver each, the prize pool would be **~250 dollars**

Brought to you by the creators of Breez Math Training, we have extensive experience teaching competition math (participants of the USA Math Olympiad Program) as well as participating in competitive programming competitions, and want to share our love for math with you all!

The math in competition will be similar to middle/high school math competitions, which can be quite difficult!

How do I register

Please register on the website!

QuickMaths now has two new levels: Sum of Squares and Prime Factorization.

Join us in the first Quickmaths Marathon 1 here from Friday Feb 23 to Friday March 1 (ending at 7:30 EST)

After the week, we'll host a live five-game Twitch showdown among the top five in each of the two categories to determine the winner.

The winners in each category will win $50 each (via Amazon Gift Card).

Good luck!

The Sum of Squares task is to write a number as the sum of at most 4 squares. For example, $$$151 = 100 + 25 + 25 + 1$$$ so an acceptable answer would be "100 25 25 1" or "25,1,25,100", etc.

The Prime Factorization task is to prime factorize the given number. For example, the prime factorization of $$$405$$$ would be "3^4 * 5" or "5^1*3^4", etc.

Hey!

My friend Daniel and I (former USA Math Olympiad participants) are hosting MathForces Contest 5 today on Saturday Feb 17 at 5:30 EST (2:30 PST). Make sure to register — would love to see you there!

Thanks all who participated in our MathDash/MathForces contest (you can see results here: Bronze Division and Silver Division

Wanted to share with the rest of you all (since it was at quite a difficult time in Moscow and India!) — feel free to take a stab at the problems here.

Just want to say that Silver #10 is one of my favorite problems of all time. Would love to share the solution here if people are curious :)

Problem 1 (Bronze Division)

Problem 2 (Bronze Division)

Problem 3 (Bronze Division)

Problem 4 (Bronze Division)

Problem 5 (Bronze Division)

Problem 1 (Silver Division) / Problem 6 (Bronze Division)

Problem 2 (Silver Division) / Problem 7 (Bronze Division)

Problem 5 (Silver Division) / Problem 8 (Bronze Division)

Problem 4 (Silver Division) / Problem 9 (Bronze Division)

Problem 3 (Silver Division) / Problem 10 (Bronze Division)

Problem 6 (Silver Division)

Problem 7 (Silver Division)

Problem 8 (Silver Division)

Problem 9 (Silver Division)

Problem 10 (Silver Division)

You are given a street of length n, where n is even. Each block on the street can hold one car.

In one move, you can move a car either forwards or backwards, as long as there is no car in the square to the left or to the right of the car.

There are n/2 total cars on the street, and your goal is to get the cars to be evenly spaced — meaning, there is exactly one open square between any two adjacent cars.

Full Problem Description, Submission Portal, and Leaderboard

The level is for Div 3 / Div 2 participants. Would encourage you all to try the question and see if you can make it onto the leaderboard :)

Hello Codeforces!

On Saturday Feb 24 at 12:00 PM EST we will host a Combinatorics MathDash Contest co-hosted by the Carnegie Mellon Informatics and Mathematics Competition! — Register here

On Tuesday Feb 27 at 7:00 PM EST we will host the seventh MathDash Contest! — Register here

Brought to you by the creators of Breez Math Training, we have extensive experience teaching competition math (participants of the USA Math Olympiad Program) as well as participating in competitive programming competitions, and want to share our love for math with you all!

The math in competition will be similar to middle/high school math competitions, which can be quite difficult!

We will host the contest on our new platform MathDash and have a separate rating system. The contest will be rated.

Who is this for?

Our target audience is a beginner or novice math competition participant or competitive programmer who wishes to improve in their mathematical problem-solving ability. We welcome everyone though! All we ask is that you have a love for math and a love for improving :)

How do I register

Please register on the website so that we can prepare and ensure we can handle the load on our platform for this competition!

We'd love to hear from you!

Please let us know in the comments below what you'd be looking for out of a math contest platform!

Hey!

My friend Daniel and I (former USA Math Olympiad participants) are hosting a live math competition on Monday Feb 5 at 7:30 EST (4:30 PST). The level of problem will be similar to the MATHCOUNTS competition (here's an example).

Would love to see signups, feel free to sign up directly on the site or through our Google Form. Also, would love to hear suggestions on groups of people whom you think this would be the right difficulty for (i.e. who should I share this with!)

Hi!

Wanted to share that my friend Daniel and I (both prolific codeforcers and Math competition nerds) are hosting an online free training program in the last week before the AIME (American Invitational Math Exam)!

We plan to send you AIME problems to your email on a daily basis (as frequently as you solve them!) and will make ourselves available to give you hints when you are stuck. We’ll adjust the difficulty of the questions in order to match the appropriate level.

If interested, sign up at https://forms.gle/1i6JHeZh4Qu3Fs7Y6 We will respond ASAP to let you know if we’re able to accommodate you.

Hope we can help you or anyone you know prepare for the AIME in a week!

Hey I've been working on this online multiplayer math game app and I thought I'd share to see if y'all like it! You can compete against others to get the highest ELO rating in different math categories. Would love all suggestions of question types and/or features!

https://www.quickmaths.io

Try to beat my high scores :)

TLDR: Try out this guess-the-song game! https://www.partyy.life/

Hi, My friend and I have been working on this guess-the-song website for a while now, and we'd really appreciate it if you could try it out and share any feedback on design, gameplay, difficulty, suggestions, or anything! This isn't really related to competitive programming except that this game's addictiveness is $$$O(n^2)$$$!!

I know the global rounds tend to have good problems, but other than those, which rounds tend to have higher quality problems? Sponsored rounds (which ones)? rounds with tons of authors? Are there any specific authors who always have incredible rounds? anyone have specific round recommendations?

Hey all,

I spent some time writing a textbook on how to efficiently convert between different bases, and thought it may be useful to those of you who are learning this for the first time.

Link: https://drive.google.com/file/d/12CeDNZO_trww-ZtGWMdSUCrhN8kcbi2U/view