UVa_Online_Judge
UVa Online Judge is an online automated judge for programming problems hosted by University of Valladolid.[1] Its problem archive has over 4300 problems and user registration is open to everyone. There are currently over 100000 registered users. A user may submit a solution in ANSI C (C89), C++ (C++98), Pascal, Java, C++11 or Python. Originally it began without the last three options, but the Java option was added in 2001, the C++11 option was added in 2014, then the Python option was added in 2016.[2]
UVa OJ also hosts contests. In the contest environment the user has a limited time to solve a small set of problems