Equations Work interview question

UML, Database Design, Database Procs,Joins, JAVA8, Azure, AWS, Socket Programming Was also asked to design a flawless car parking algorithm/program in JAVA that assumes a sensor for detecting a car standing underneath and then fill up the parking in the most optimum way so that Hatchbacks, Sedans, Saloons and Limousines can be parked better in the parking spots of same size.