C programming on Linux - Multithreaded

: Office Hours Multi-Thread Programming - You have been hired by the School of Computer Science at FIU to write code to help synchronize a professor and his/her students during office hours. The professor, of course, wants to take a nap if no students are around to ask questions; if there are students who want to ask questions, they must synchronize with each other and with the professor so that (i) no more than a certain number of students can be in the office at the same time because the office has limited capacity, (ii) only one person is speaking at a time, (iii) each student question is answered by the professor, (iv) no student asks another question before the professor is done answering the previous one, and (v) once a student finishes asking all his/her questions, he/she must leave the office to make room for other students waiting outside. You are to provide the following functions:
Professor(). This functions starts a thread that runs a loop calling AnswerStart() and AnswerDone(). See below for the specification of these two functions. AnswerStart() blocks when there are no students around.
Student(int id). This function creates a thread that represents a new student with identifier id that asks the professor one or more questions (the identifier given to your function can be expected to be greater or equal to zero and the first student's id is zero). First, each student needs to enter the professor’s office by calling EnterOffice(). If the office is already full, the student must wait.