(Java)

Given a pointer to the root of a binary tree and a pointer ' p ' to a given node in the tree and a second pointer ' q ' to another node in the tree write a routine which will return the total number of nodes in the tree that are between levels p and q. You can assume that p is on a smaller level than q (higher in the tree for example level 3) and q is on a higher level (for example level 5). In this case I would want to know the number of nodes on level 4 only. If p was on level 2 and q on level 5 I would want to know the total number of nodes on levels 3 and 4. Remember don't hardcode values for p and q you must also figure out which level they are on