see title ^
Go to the question. there is a submit bar on the right side corner. You can choose the language of your choice from the drop down menu and you can then either paste your solution in the box or upload the source file and click submit.
You might not get SUBMIT button. That means either the contest has ended or you’re not logged in according to the contest requirements (team or individual).
In that case, check if the problem is in practice section by just removing the keyword for the contests (official).
For example:
http://www.codechef.com/FEB14/problems/TWODOGS will lead you to the contest page, and
http://www.codechef.com/problems/TWODOGS will take you to the same problem in practice section.
As the contest FEB14 has ended, you can still submit your solution by following the link to the practice section for the respective problem(s).
when clicking on Submit Button shows Restricted Content …Logged in than also …