adjacent vs adjoining

1a. We had adjacent rooms in the hostel when we were studying.
1b. We had adjoining rooms in the hostel when we were studying.
2a. We were living in the two buildings adjoining each other.
2b. We were living in the two buildings adjacent to each other.
Please correct the above and comment.
Thanks.

1a. We had adjacent rooms in the hostel when we were studying.
1b. We had adjoining rooms in the hostel when we were studying.
2a. We were living in the two buildings adjoining each other.
2b. We were living in the two buildings adjacent to each other.

“adjacent” and “adjoining” do not mean the same thing.
oxfordlearnersdictionaries.com/?cc=global

Note that sometimes hostel / student hostel = budget accommodation for travellers, particularly people of typical student age. It does NOT ALWAYS refer to a room on the campus of a university or college.

Beeesneees,
The link - oxfordlearnersdictionaries.com/?cc=global
does not give enough explanation showing the difference between “adjacent” and “adjoining”.
Please give some more examples to explain the difference between “adjacent” and “adjoining”.
Thanks.

adjacent - next to each other
adjoining - joined together.

adjacent rooms - self contained rooms, side by side. To get from one room to the other, you must go outside into the corridor or hallway.
adjoining rooms - rooms with a shared door as well as the usual main door, so that you can walk from one to the other without going outside into the corridor.