There are n students (numbered 0 through n-1) in class, and they need to be partitioned into teams. The teams do not need to have the same size-some can have size 1, some can have size 2, and so on with no and others want not to be on the same team. Write a Python function all_happy(n, req_same, req_different) that determines whether it's possible to satisfy all requests (returning True if possible and False if not). Here, req_same is the list of all pairs of students requesting to be on the same team, and req_different is the list of all pairs of students requesting to be on different teams. The running time should be O(n+mlogn) where m is the total number of requests