Firstly I thought it was only some bug with the server and the administrator would fix it soon. But later I discovered that it seemed to be a new change to this website. Why Codeforces doesn't provide data now? I think it's a very nice function for users to find their mistakes and correct them. Otherwise we would take lots of time to read the code or use random data to find our mistakes, which is obviously a long-time job and can't ensure us to finish it. Among all the code websites I use, only Codeforces provide data, and that's why I like to use it as training. But now everything changed. Could you please explain why you do this? Thanks!
Today I found flaw for a CF problem in my solution with manual testing, and i felt good after that.
But some codes are really long and sometimes it's impossible to debug only by manual work.
Completely agree with you. Looking at the test cases is what helped me get into competitive programming. Otherwise, I probably would have quit after solving 5-10 problems.
Altough other websites like HackerRank and HackerEarth show test cases, it's in a very inconvenient format. CodeForces provides test cases in a very slick and clean format.
In this comment , Mike has said its a temporary situation. Hopefully this is rolled back soon.
Fixed tonight. It was a lack of free space on partition with test results. Moved the data to the larger disk.
Thank you for the work! That will be best!