Hey Everyone, Next week we are hosting SRM 800!

SRM 800 is not just any other SRM but a big milestone for the competitive programming community. We at Topcoder started SRMs back in 2001 to start a culture of fortnight rated contests and in these 20 years, Topcoder with the help of the community has successfully been able to organize 800 rounds.

This is a moment to cherish and celebrate all the contributions members have done over these years. It takes a lot to organise a round, from writers, testers, admins, editorialists, the product development team, to all the competitors who compete with all their passion and encouragement.

SRM 800 is taking place on February 13, 2021 and we are organizing a Virtual Party. Register Now! Join us as we celebrate this SRM milestone with a panel discussion with veterans including misof, Petr, neal_wu and tourist, a post-match analysis with our top problem writers, and some great informational sessions.

Exclusive SRM 800 T-shirt for:

• 25 Top members from both divisions to get an exclusive SRM 800 T-shirt

• 25 Top Newbies* other than the Top 25 from Div II

• 25 Random Participants (other than the Top 25 from both divisions and 25 Newbies) 

• Veteran Competitors** in Top 50 from both divisions earn an exclusive, vintage Topcoder t-shirt.

Cash prizes as follows:

Div I 

• 1st place: $150

• 2nd place:$100

• 3rd place: $75

Div II

• 1st place: $150

• 2nd place:$100

• 3rd place: $75

• Top Scoring Newbie*: $100

*Cash and t-shirt prizes for newbies is valid only to Topcoder members who registered before 23:59 UTC-5 February 3, 2021 and have never participated in an SRM before.

**Veteran Competitors are those who last competed in a rated round before December 31, 2014.

Hope to see most of you compete and be a part of this milestone contest!

SRM 800 is scheduled to be held on Saturday, February 13 at 12:00 UTC -5. Registration is now open for the SRM in the Arena or Applet and closes at 11:55 UTC-5. The coding phase will start at 12:05 UTC-5, so make sure that you are all ready to go. Click here to what time it starts in your area

Best of luck!
- the Topcoder Team

Topcoder SRM 799 is scheduled to start at 12:00 UTC-5 on February 6, 2021.

Registration is now open for the SRM in the Arena or Applet and closes at 11:55 UTC-5. The coding phase will start at 12:05 UTC-5, so make sure that you are all ready to go.

Thanks to IH19980412 for writing the problem set. Also thanks to misof for testing and coordinating the round.

This SRM will award points towards Stage 3 of TCO21 and also the qualifications for TCO21 Regional Events

Some Important Links:: Match Results (match results, rating changes, challenges, individual test case results), Problem Archive, Problem Writing, Algorithm Rankings, Editorials and Older Editorials(SRM 710 and before),

Best of luck!
- the Topcoder Team

. . . .

UPD: The contest will start an hour later from the scheduled time. It will now start at 13:00 UTC-5 on February 6, 2021

Marathon Match 123

Topcoder MM 123 - **Jewels** is now live!

Problem Setter: JacoCronje Problem Testers: dimkadimon and kphmd

Problem Overview: 
Jewels is a game where you must construct horizontal or vertical lines of the same type of jewel on an NxN grid. Each cell of the grid is one of C types of jewels. In each move, you can swap any two jewels. Jewels are removed from the grid when they form a horizontal or vertical line of at least 3 matching jewels next to each other. Jewels above empty spaces fall down and can form more matching horizontal or vertical lines which will again be removed and the process repeats. Such an event is called a chain reaction. The more chain reactions you create, the more points you will score. Your task is to play the game for 1000 moves and remove as many jewels from the grid with as many chain reactions as you can. Here is a partial animation of a solution for seed=1.

Here is an animation of a solution for seed=1. (You can see the working animation here: https://mailchi.mp/topcoder/marathon-match-123)

Single Round Match 798

Topcoder SRM 798 is scheduled to start at 12:00 UTC-5 on Jan 23, 2021.

Registration is now open for the SRM in the Arena or Applet and closes at 11:55 UTC-5. The coding phase will start at 12:05 UTC-5, so make sure that you are all ready to go.

This SRM will award points towards Stage 3 of TCO21 and also the qualifications for TCO21 Regional Events

Some Important Links:: Match Results (match results, rating changes, challenges, individual test case results), Problem Archive, Problem Writing, Algorithm Rankings, Editorials and Older Editorials(SRM 710 and before),

Best of luck!
- the Topcoder Team

Rookie SRM 2

TCO20 Special Rookie SRM 2 is scheduled to start at 11:00 UTC-5 on January 15, 2021. 

Registration is now open for the Rookie SRM in the Arena or Applet and closes at 10:55 UTC-5. The coding phase will start at 11:05 UTC-5, so make sure that you are all ready to go. Click here to what time it starts in your area.

The Rookie SRM is open to everyone and has some special cash prizes. It will only be rated for members who:
- Have never competed in Rated Algorithm Contests OR
- Have competed in equal to or less than 5 rounds OR
- If their current rating is less than 800 rating points.

Prizes:

Topcoder T-shirt for Top 20
*Prizes are only for members who are eligible to be rated

Choose Your Competition Arena

There are two ways to compete in Algorithm Competitions or Single Round Matches (SRMs). Read here to find which works best for you.

Some Important Links:: Match Results (match results, rating changes, challenges, individual test case results), Problem Archive, Problem Writing, Algorithm Rankings, Editorials and Older Editorials(SRM 710 and before),

Best of luck!
- the Topcoder Team

UPD: T-shirt Winners: https://apps.topcoder.com/forums/?module=Thread&threadID=966750&start=0&mc=1#2448390

Single Round Match 797

Topcoder SRM 797 is scheduled to start at 12:00 UTC-5 on Jan 9, 2021.

Registration is now open for the SRM in the Arena or Applet and closes at 11:55 UTC-5. The coding phase will start at 12:05 UTC-5, so make sure that you are all ready to go. Click here to what time it starts in your area.

This SRM marks the beginning of Stage 3 of TCO21 and also the qualifications for TCO21 Regional Events

Some Important Links:: Match Results (match results, rating changes, challenges, individual test case results), Problem Archive, Problem Writing, Algorithm Rankings, Editorials and Older Editorials(SRM 710 and before),

Best of luck!
- the Topcoder Team

Single Round Match 796

Topcoder SRM 796 is scheduled to start at 07:00 UTC-5 on December 23, 2020.

Registration is now open for the SRM in the Arena or Applet and closes at 06:55 UTC-5. The coding phase will start at 07:05 UTC-5, so make sure that you are all ready to go. Click here to what time it starts in your area.

Thanks to misof for writing the problem set and coordinating the round. Get ready for some exciting Christmas themed problems. :)

Some Important Links:: Match Results (match results, rating changes, challenges, individual test case results), Problem Archive, Problem Writing, Algorithm Rankings, Editorials and Older Editorials(SRM 710 and before),

Best of luck!
- the Topcoder Team

Marathon Match 122

Topcoder MM 122 - **SuperMinesweeper** is now live!

Problem Setter: dimkadimon
Problem Testers: JacoCronje and kphmd

Problem Overview: 
Super Minesweeper is a game where you must locate **M** mines that have been hidden somewhere on an **N**x**N** grid. Each cell of the grid is either a mine or a value. A value in cell X represents the number of mines in cells Y whose squared Euclidean distance from cell X is **D** or less. The game begins with all cells hidden except for a single cell with a zero whose location is provided. In each move, you can uncover one cell of the grid. Unlike the classic Minesweeper, the game continues when you uncover (hit) a mine, but you lose points. Your task is to uncover as many values as possible while minimizing the number of mines you have hit. In particular, your raw score is the percentage of values uncovered divided by the number of mines you have hit plus one.

Here is an animation of a solution for seed=1. (You can see the working animation here: https://mailchi.mp/topcoder/marathon-match-122)

Single Round Match 795

Topcoder SRM 795 is scheduled to start at 12:00 UTC-5 on December 12, 2020.

Registration is now open for the SRM in the Arena or Applet and closes at 11:55 UTC-5. The coding phase will start at 12:05 UTC-5, so make sure that you are all ready to go. Click here to what time it starts in your area.

Thanks to jy_25, majk and misof for writing the problem set. Also thanks to misof for testing and coordinating the round.

Some Important Links:: Match Results (match results, rating changes, challenges, individual test case results), Problem Archive, Problem Writing, Algorithm Rankings, Editorials and Older Editorials(SRM 710 and before),

Best of luck!
- the Topcoder Team

Topcoder SRM 794 is scheduled to start at 11:00 UTC-5 on December 4, 2020.

Registration is now open for the SRM in the Arena or Applet and closes at 10:55 UTC-5. The coding phase will start at 11:05 UTC-5, so make sure that you are all ready to go. Click here to what time it starts in your area.

Problem Writers: misof and laoriu

Learn more about problem writing and testing opportunities.

Choose Your Competition Arena

There are two ways to compete in Algorithm Competitions or Single Round Matches (SRMs). Read here to find which works best for you.

Some Important Links

Learn more about problem writing and testing opportunities.

Best of luck!
- the Topcoder Team

Topcoder is almost 20 years old now. Over these years we have had many great competitors/competitive programmers. Always wanted to know where they are now? — Join us as we bring the stories of some of the greatest we have had.

Starts in 1:15 hr

Join us on Hopin to Chat with the greats: https://hopin.to/events/topcoder-tco20-thurs-nov19

It will also be streamed on

• Youtube — https://www.youtube.com/watch?v=h2GODsoVmzo
• Facebook — https://www.facebook.com/topcoder
• Twitch — https://www.twitch.tv/topcoder_official

TCO20 Special Rookie SRM 1

TCO20 Special Rookie SRM 1 as part of the 2020 Topcoder Open is scheduled to start at 13:00 UTC-5 on November 18, 2020. 

Registration is now open for the Rookie SRM in the Arena or Applet and closes at 12:55 UTC-5. The coding phase will start at 13:00 UTC-5, so make sure that you are all ready to go. Click here to what time it starts in your area.

The Rookie SRM is open to everyone and has some special cash prizes. It will only be rated for members who:
- Have never competed in Rated Algorithm Contests OR
- Have competed in equal to or less than 5 rounds OR
- If their current rating is less than 800 rating points.

Prizes:
1st: $300
2nd: $200
3rd: $100
$25 for 5 other random participants
Topcoder T-shirt for Top 30
*All prizes are only for members who are eligible to be rated

Choose Your Competition Arena

There are two ways to compete in Algorithm Competitions or Single Round Matches (SRMs). Read here to find which works best for you.

Some Important Links

Learn more about problem writing and testing opportunities.

Best of luck!
- the Topcoder Team

UPD Thanks to everyone who competed! Please find the editorials here. Congratulations to the all the winners:

Hi Everyone,

TCO20 Algorithm Finals – the most awaited Topcoder tournament of the year is almost here. Will tourist reign supreme or does someone else in the group have what it takes?

16 top-rated members will be competing in the next few weeks for the ultimate title of Topcoder Open. 

Here’s how the semifinal rounds look: 

Semi-Final 1 Group

Semi-Final 2 Group

Live Broadcast

TCO20 Algorithm Rounds will be broadcasted live and you’ll be able to listen to the amazing hosts Errichto and Lewin during the contest as they will explain the problems, do live commentary, and show you the competitors’ screens. They will be joined by some amazing guest competitors on each broadcast and also there are some exciting post match interviews planned too.

Find the full schedule with all the details and signup links to the event here. 

TCO20 Special Rookie SRM with Prizes

If you are new to Topcoder, we are also organising an interesting educational beginner contest with prizes after Semifinal 2:

TCO20 Special Rookie SRM

Wednesday, November 18, 2020 13:00 UTC-5

The Rookie SRM is open to everyone and has some special cash prizes. It will only be **rated** for members who have competed in equal to or less than 5 rounds or if their current rating is less than 800 rating points.

Prizes:

• 1st :: $300
• 2nd :: $200
• 3rd :: $100
• $25 for 5 other random participants
• Topcoder T-shirt for Top 30
• *All prizes are only for members who are eligible to be rated.

Stats — Algorithm Finalists Head to Head

We hope to see you there!

Topcoder SRM 793 is scheduled to start at 21:00 UTC-5 on November 4, 2020.

Registration is now open for the SRM in the Arena or Applet and closes at 20:55 UTC-5. The coding phase will start at 21:05 UTC-5, so make sure that you are all ready to go. Click here to what time it starts in your area.

Learn more about problem writing and testing opportunities.

Choose Your Competition Arena

There are two ways to compete in Algorithm Competitions or Single Round Matches (SRMs). Read here to find which works best for you.

Some Important Links

Learn more about problem writing and testing opportunities.

Best of luck!
- the Topcoder Team

Marathon Match 121

Topcoder MM 121 - SoccerTournament is now live!

Problem Setter: dimkadimon
Problem Testers: JacoCronje and kphmd

Problem Overview: 
N teams play in a round-robin soccer tournament where each team plays every other team once. Each game has three possible outcomes: win for first team, win for second team or a draw. If a team wins the game then it receives **W** points. If the game is a draw then both teams receive **D** points. The losing team receives no points. Your task is to reconstruct the result of each game given the total number of goals scored, goals conceded and points earned by each team. You will receive 1 point for predicting a game's outcome (win, loss, draw) correctly. You will receive additional 2 points for also predicting the game's exact score.

Register Now!

Best of luck! 
- the Topcoder Team

Topcoder SRM 792 is scheduled to start at 07:00 UTC-4 on October 23, 2020

Registration is now open for the SRM in the Arena or Applet and closes at 06:55 UTC-4. The coding phase will start at 07:05 UTC-4, so make sure that you are all ready to go. Click here to what time it starts in your area.

Learn more about problem writing and testing opportunities.

Choose Your Competition Arena

There are two ways to compete in Algorithm Competitions or Single Round Matches (SRMs). Read here to find which works best for you.

Some Important Links

Learn more about problem writing and testing opportunities.

Best of luck!
- the Topcoder Team

Topcoder SRM 791 is scheduled to start at 12:00 UTC-4 on October 17, 2020.

Registration is now open for the SRM in the Arena or Applet and closes at 11:55 UTC-4.The coding phase will start at 12:05 UTC-4, so make sure that you are all ready to go. Click here to what time it starts in your area.

Thanks to laoriu for writing the problem set. Also thanks to misof for testing and coordinating the round.

Choose Your Competition Arena

There are two ways to compete in Algorithm Competitions or Single Round Matches (SRMs). Read here to find which works best for you.

Some Important Links

Learn more about problem writing and testing opportunities.

Best of luck!
- the Topcoder Team

Topcoder MM 120 -  ReversalSort is now live!

Problem Setter: dimkadimon
Problem Testers: JacoCronje and kphmd

Problem Overview: 
You are given a sequence S containing **N** numbers in the range [0, **K**). Your task is to sort this sequence into monotonically increasing order, in a way that incurs the smallest penalty. You are allowed to select any contiguous sub-sequence of numbers and reverse their order. Formally, if the sub-sequence is (S[i], S[i+1], ..., S[k-1], S[k]), where 0 <= i < k < **N**, then its reversal is (S[k], S[k-1], ..., S[i+1], S[i]). The penalty incurred by this reversal is floor[(k-i+1)^**X**], where **X** is a given penalty parameter. Your task is to minimize the total penalty incurred by all the reversals.

Register Now!

Best of luck! 
- the Topcoder Team

Topcoder SRM 790 is scheduled to start at 11:00 UTC -4, Sept 10, 2020.

Registration is now open for the SRM in the Arena or Applet and will closes at 10:55 UTC-4. The coding phase will start at 11:05 UTC-4, so make sure that you are all ready to go.

Thanks to nikhil_chandak for writing the problem set. Also thanks to misof for testing and coordinating the round.

Choose Your Competition Arena

There are two ways to compete in Algorithm Competitions or Single Round Matches (SRMs). Read here to find which works best for you.

Some Important Links

Good luck to everyone!

The Parallel Round of fourth Algorithm Competition Online Round of the 2020 Topcoder Open has arrived! Parallel Round 4 will be held on Saturday, Sept 5 at 12:00 UTC -4.

The match will be **rated**

Please note that you must register for this round in the Arena. Registration is now open for the round in the Arena or Applet and will close at 11:55 UTC-4. The coding phase will start at 12:05 UTC-4, so make sure that you are all ready to go. See what time Round 4 starts in your area.

Don’t know how to compete in Topcoder Algorithm Competitions?

Check out this guide to successfully compete in an algorithm match.

You can compete using:

• Topcoder Java Applet - You can refer to this guide here to set up the applet. (Note that those who have Java 8 installed on their machine will see a security issue — You will have to add Topcoder in security exceptions in Java Control Panel. Please refer to the details in the guide.)
• Topcoder Web Arena(Beta) - Please watch this video for step by step guide

Best of luck to you in the Arena!

- The Topcoder Community team

Topcoder SRM 789 is scheduled to start at 13:00 UTC -4, August 30, 2020.

Registration is now open for the SRM in the Arena or Applet and will closes at 12:55 UTC-4. The coding phase will start at 13:05 UTC-4, so make sure that you are all ready to go.

Thanks to square1001, lg5293 and misof for writing the problem set. Also thanks to misof for testing and coordinating the round.

Choose Your Competition Arena

There are two ways to compete in Algorithm Competitions or Single Round Matches (SRMs). Read here to find which works best for you.

Some Important Links

Good luck to everyone!

The TCO20 Algorithm Round 3B and Parallel Round of TCO20 Algorithm Round 3B is scheduled to be held on Tuesday, August 18 at 07:00 UTC -4.

The match will be **rated**.

Please note that you must register for this round in the Arena. Registration is open for the round and closes at** 06:55 UTC -4. **The coding phase will open at 07:05 UTC-4.

Please note that you must register for this round in the Arena. Registration is now open for the round in the Arena or Applet and will close 5 minutes before the match begins, so make sure that you are all ready to go. Click here to what time it starts in your area.

Members eligible to compete in the Parallel Round include:
- Members who did not qualify for Round 3
- Members who advanced to Round 4 from Round 3A
- Qualified for Round 4 or TCO20 Algorithm Finals from Online Stages 1,2 and 3

Don’t know how to compete in Topcoder Algorithm Competitions?

Check out this guide to successfully compete in an algorithm match.

You can compete using:

• Topcoder Java Applet - You can refer to this guide here to set up the applet. (Note that those who have Java 8 installed on their machine will see a security issue — You will have to add Topcoder in security exceptions in Java Control Panel. Please refer to the details in the guide.)
• Topcoder Web Arena(Beta) - Please watch this video for step by step guide

Best of luck to you in the Arena!

• The Topcoder Community team

The TCO20 Round 3A and Parallel Round are scheduled to be held on Saturday, August 1 at 12:00 UTC -4.

The match will be rated

Please note that you must register for this round in the Arena. Registration is now open for the round in the Arena or Applet and will close 5 minutes before the match begins, so make sure that you are all ready to go. Click here to what time it starts in your area.

Members eligible to compete in the Parallel Round include:
- Members who did not qualify for Round 3
- Qualified for Round 4 or TCO20 Algorithm Finals from Online Stages 1,2 and 3

Don’t know how to compete in Topcoder Algorithm Competitions?

Check out this guide to successfully compete in an algorithm match.

You can compete using:

• Topcoder Java Applet - You can refer to this guide here to set up the applet. (Note that those who have Java 8 installed on their machine will see a security issue — You will have to add Topcoder in security exceptions in Java Control Panel. Please refer to the details in the guide.)
• Topcoder Web Arena(Beta) - Please watch this video for step by step guide

Best of luck to you in the Arena!

Topcoder MM 119 -  HardestMaze is now live!

Problem Setter: dimkadimon

Problem Testers: JacoCronje and kphmd

Problem Overview: 
You want to create a maze to test the navigating ability of robot vacuum cleaners. The maze is to be designed on an **N**x**N** grid floor, whose cells are either empty ('.') or contain a wall ('#'). There are **R** robots and each robot must visit **T** target locations. In particular, each robot **r** begins in location **Starts[r]** and must visit every location given in **Targets[r]**. The robots do not need to return to their starting location at the end of their journey. The robots can only move through adjacent (horizontally or vertically) empty cells. The robots can see the entire maze and will choose the *shortest* path that visits all their target locations. Some paths of the robot may overlap and these are all counted towards the total distance. Your goal is to make the maze as hard as possible, ie., to maximize the total distance travelled by all the robots.

For example, here is a solution for seed=1. There are 2 robots (crosses) and each must visit 2 target locations (circles). The shortest path for each robot is shown with a different colour. Note that some paths may overlap — this is ok as robots do not interfere with each other.

Register Now!

Best of luck! 
- the Topcoder Team

Topcoder SRM 788 is scheduled to start at 07:00 UTC -4, July 24, 2020. Registration is now open for the SRM in the Arena or Applet and will close at 06:55 AM, so make sure that you are all ready to go. Please note that the coding phase will begin at 07:05 AM UTC -4 but the registration will still close at 06:55 AM UTC -4.

Thanks to square1001 for writing the problem set. Also thanks to misof for testing and coordinating the round.

This is the first SRM of Stage 1 of TCO21 Algorithm Tournament.

Choose Your Competition Arena

There are two ways to compete in Algorithm Competitions or Single Round Matches (SRMs). Read here to find which works best for you.

Some Important Links

Good luck to everyone!