I hope you could help me with the cash, less comfortable problem. I'm receiving this error message but I'm not sure what's causing the error message. Thank you very much in advance!
The screen shot would be easier to read if larger, or simply pasted text. It says:
cannot open file cash: Is a directory.
If if the full path to the file being compiled should be pset1/cash/cache.c, but it is actually pset1/cash.c, the presence of a directory called 'cash' will cause that error. Try running 'pwd' and 'ls' yourself. If you see this:
~/pset1/ $ pwd
~/pset1/ $ ls
cash/ cash.c hello/ population/
this sequence of commands should set it right:
~/pset1/ $ mv cash.c cash
~/pset1/ $ cd cash
~/pset1/cash/ $ ls
~/pset1/cash/ $ make cash