Fefer_Ivan's blog

Codeforces Groups
By Fefer_Ivan, 11 years ago, translation, In English

Hello, Codeforces!

Today I would like to tell you about new Codeforces feature: about groups. Now you can create a group , invite people into it, add members to group and organize contests inside a group.

Create a Group

Only Div.1 coders can create a group. Good reason to increase rating, right? If you have rights to create a group on the Groups page, it will be a special link. Except name, you can specify:

  • description (feel free to use simple HTML)
  • logo: it will shine on each group’s page!
  • related to group website URL  

Visibility

There are public and private groups. Public groups are visible to all users and private are visible only to members of the group.

Public groups can be created only by participants with coaching rights. Do not create public groups like: for functionallity testing, not interested for wide range of users, which don't contain well-prepared contests. All public groups should have appropriate name, description, etc. Codeforces Team will moderate public groups.

Members of a private group and their friends can access the group by a special link like codeforces.com/group/{groupCode} You can distribute it among potential group members.

Registration Policy

There are three possible policy values: open enrollment, moderated registration, registration by invitation only.

  • Open enrollment is also called “without confirmaion” — any user will be able to join the group.
  • Moderated registration is also called “by confirmation” — any person will be able to apply to the group, but manager should confirm application to be valid.
  • By invitation: the only way to join a group is receive invitation from a manager.

Roles in Group

Each group member has a role: regular member or a manager . If you’ve created a group, you are the group owner and manager by default. If you wish to share the management responsibility with others, you can promote a member to become manager of the group. Only managers can invite other users to the group, to change the role of other members and most important — to add contests.

How to add a contest to group?

Managers can add contests to a group Once your group is created, managers can add contests. They need only click into special link on the group title page and choose a contest. Feel free to use autocompletion to find the contest: it knows about contest-id and contest name. The group standings page has special mode to filter by group members.

What about private contests in group?

Attention. If you add your private contest to the group, it will be available to all members of the group. Thus, it is the way to organize private contests for group and do not share them to the Gym.

Actually, you can add contest to the group, if it is either a public or you can manage it. That is, it is impossible to add someone's private contest.

Example

As an example, we have created a public group, which brings together all the trainings from Codeforces Trainings Season 01, which are held on Wednesdays at 12:10 (UTC).

More is coming

For sure, we will add more featires in groups later. Leave ideas in comments!

Ivan Fefer,
Codeforces Software Engineer

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Comments Comments (27)
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11 years ago, # |
← Rev. 2   Vote: I like it +65 Vote: I do not like it

I think this can be a really awesome feature added to the groups if there is a provision to create contests with your own choice of problems. That is, I will be able to create a contest that only the members of the groups can participate in, and I can select problems from the problemset on codeforces. This should create a contest like environment where all the members are in a room and the points system can be similar to the codeforces round. Hacking provision can be added if possible. This will be really helpful when a group of people want to practice some particular topic. Example: If I along with some friends want to practice DP, I will make a contest, set the time and duration, search and add 4-5 problems on DP that none of us has done before and then we can compete like a normal codeforces round.

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11 years ago, # |
← Rev. 2   Vote: I like it +26 Vote: I do not like it

It will be awesome if it support to use problems from different rounds to make a new contest.

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11 years ago, # |
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This would be better if we could add contest from Polygon too.I mean , our own contests and problems.

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    11 years ago, # ^ |
      Vote: I like it -8 Vote: I do not like it

    I think it's a very good idea, but it may needs a stronger judge machine and some more strict rules (may be only grandmasters can add their own contests ...)

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    11 years ago, # ^ |
      Vote: I like it +11 Vote: I do not like it

    Red and yellow users can add own contests to gym. And then add it contests to group.

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11 years ago, # |
← Rev. 2   Vote: I like it +17 Vote: I do not like it

I was thinking about this recently, since I got coach mode in Gym. I thought "it'd be good to be able to organize small contests here, but without spamming the site".

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11 years ago, # |
← Rev. 3   Vote: I like it 0 Vote: I do not like it

Thank you very much for such great feature I wonder if I can delete group after creating it ? Because I want to create a group for testing the new feature and I don't want to stuck with the group forever I also wonder if the name , description and logo of group can be changed or not?

Edit: can I create my own contests and problems or only I can choose from gym?

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11 years ago, # |
← Rev. 2   Vote: I like it +3 Vote: I do not like it

Is it okay to create university public groups(with >100 members) like there is one as for Cambridge?

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11 years ago, # |
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This is great!

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    11 years ago, # ^ |
    ← Rev. 2   Vote: I like it -7 Vote: I do not like it

    [Deleted]

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      11 years ago, # ^ |
        Vote: I like it +3 Vote: I do not like it

      The answer is in the blog post: to give extra motivation for increasing your rating :D

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        11 years ago, # ^ |
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        Oh, I just saw. Sorry for asking!

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11 years ago, # |
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if possible, please add the option to sort the members of a group based on their rating. it would certainly help a lot. thanks!

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11 years ago, # |
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Just to clarify, are group members in trouble if they lose their Division 1 standing? (As you can see, I'm teetering on the edge :D)

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6 years ago, # |
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I would like to ask if there are any restrictions on the number of groups created, for example, I can create up to five groups. Or at the moment I can create it without limit.

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4 years ago, # |
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Hi how do I register teams for contests in CF groups?

After I click 'register them', nothing happens.

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4 years ago, # |
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I created a group sometime back which I want to leave now but I am not able to find any such option. is there any way to leave the group if I am the creator???

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    4 years ago, # ^ |
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    can u tell me how to leave even if one is not the creator

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      4 years ago, # ^ |
        Vote: I like it 0 Vote: I do not like it

      Open the group, you will see an option to leave on the right.

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4 years ago, # |
  Vote: I like it +25 Vote: I do not like it

Hello,

Sorry to bump this thread up after so long, but how do you disable the common status in groups? I made a private contest in a group, with private rank list and status, but participants were able to use the group status to see the results of other's submissions. Does anyone know a fix to this?

Thanks!

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    4 years ago, # ^ |
      Vote: I like it +3 Vote: I do not like it

    You would have created a mashup and added that in the group, right?? If yes, you should be able to see Can participants view common status?: in contest settings. I think unchecking this should be fine.

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      4 years ago, # ^ |
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      Yes, in the mashup we unselected "Can participants view common status?" and we also unselected "Allow standings?:". This problem arises despite both these settings.

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