[Unknown_Sniper]

Its a she? wow... please tell me shes hot.
Does your building have an elevator or just stairs? I would block off the stairs near the bottom floor with as much useless shit from the dorm rooms as possible, and fuck up the elevator. Then I would rig a trash chute with some rope for a quick escape. You would have to find food which is were the difficult part comes in. Do you risk running to the cafe for food, or do you try and tough it out with what people have in their rooms?
You must also consider those that are weak minded/hearted. Would they be able to kill a zombie if they had to? Would they freak out and break down your barriers to try and escape? These people must be dealt with before they can cause any major damage/ your death. Remember that in a survival situation you come first, and everyone else comes second.