It is difficult to write bug-free programs. A good debugger is helpful tracking down errors. On the Tardis cluster (public ITET computer room Linux workstations) we recommend to use DDD (Data Display Debugger). DDD is a graphical user interface frontend (GUI) for a variety of command line debuggers that accompany the respective programming languages, e.g. the gdb debugger that belongs to the gcc/ g++ compiler suite (similarly, DDD-debugging of programs written in Java, Perl, Python and other languages is also supported).
For a current list of all supported languages and features, consult the DDD manual (man ddd).