Hi . I was looking for 2-sat problem for training and i found one ... but when i click on the tag , it says "Please, use a valid tag."
Hi . I was looking for 2-sat problem for training and i found one ... but when i click on the tag , it says "Please, use a valid tag."
When I was blue for the first time I was able to change tags I'm not sure, but I think I had this possibility But now I can't do that Why?
You should be at least a div1 user to do that. ;)
It looks that it changed a few months ago, so now you have to be purple.
This bug was discusssed some time ago, but not fixed.
http://codeforces.com/blog/entry/15013
All still