There are lot of user on the codeforces those have similar issue.

This happens many time with us that we have solved or cleared concept of a problem and don't need to submit that problem. But the problem comes when we solve some problems from problemset than we can only filter problems with the tag,difficulty level but we don't have any feature to know that we have solved some particular problem previously.

Due to this we also face problem when make custom contests. like let's suppose we are making custom contest and we don't have any archive option or similar filter facility than he has to read that problem to add in his custom contest that is not a good idea to read a contest problem before the contest.

I know Codeforces is really so cool and i also love this site and Codeforces Community So i request to tell me if Codeforces have any similar functionality or if not than i request MikeMirzayanov to add an additional "Archive Problem" feature on Codeforces.

If we have an additional feature or some kind of filter to know which problems are solved or not by a particular group users so there will be easiness to make a custom contest or compete with peer.

I know many of us have many suggestion to add something new feature on Codeforce So please share all of your suggestion ,all of you are welcome.

Thank You Codeforces to give such an amazing community to learn a lot and also sorry for not a good writing skill.