AtCoder submissions, solutions, and practice
Similar to Codeforces, I take AtCoder tests to practice for USACO and also to try and improve my actually rating. See my profile in the AtCoder page.
To find the problems on the AtCoder website use enter the URL "https://atcoder.jp/contests/(folderName)/". Furthermore, to my standings enter "https://atcoder.jp/contests/(folderName)/standings?watching=Magmamite135".
If I take an "Official" (rated) test then the top of the file will say "Official: " followed by the status of the code (Correct, Incorrect, ...)