These are my potentially wrong solutions to the tasks for complexity theory at HTWG Konstanz in WS20/21. It is a configured IntelliJ project that contains the proposed library https://introcs.cs.princeton.edu/stdlib and https://bintray.com/algs4/maven/algs4 (both GNUGPLv3) and makes use of it. After cloning the repo just "open" it with IntelliJ and you will be good to go.