please help ASAP

Given: struct exam int s;//start time of exar int f;//finish time of exam int p://exam priority (lowest number=highest priority) //assume that priorities may change but once an exam is being held in the hall it cannot be interrupted }; struct hall{ exam current_exam;//the current exam being held in the hall }; Suppose we have a set of exams to be scheduled in n halls. Each exam has a priority. Assume that priorities may change but once an exam is being held in the hall it cannot be interrupted. Give a greedy algorithm to determine the maximum size set of non-overlapping exams to be scheduled using n halls. What is the worst case run time of your algorithm