For the medium to hard ones you just have to break it down line by line. What helps me the most is desk checking it or implementing it into Visual Basic (or whatever language your using) and seeing what happens.
Specifically for sorting algorithms, I found that it was easier to understand once...
so if i were to do psychology, i would have to pick something from this list? http://www.handbook.unsw.edu.au/vbook2015/brCoursesBySubjectArea.jsp?studyArea=PSYC&StudyLevel=Undergraduate
Ok so far ive enrolled into the core courses and I have one elective left and not sure what to pick since i cant seem to pick any of the COMP electives atm. any advice and recommendations here would be great. also what was your 1st elective?