The dorms where-when I went to college varied a little. Most were as Billhrny described. A few had a bathroom per two double-occupancy rooms, with a few of the rooms being single-occupancy and a couple of them housing four people. It was a common practice to try to get people that you were already friends with as roommates, and the dorm management usually tried to accommodate such requests.

There were also university-run apartments for students with families, who tended to be foreigners a lot of the time. I never saw the inside of one of those however.