In the course we have just left scratch, and have started using ide50. Following along with the course, im trying to find where to download the required workspace files.
It is harder to find than it should be, see https://cdn.cs50.net/2016/spring/psets/4/pset4/pset4.html#getting_started
basically you need to run something like
i=4; wget http://cdn.cs50.net/2015/fall/psets/$i/pset$i/pset$i.zip; unzip pset$i.zip