Reimplement Exercise E15.4 so that the keys of the map are objects of class Student. A student should have a first name, a last name, and a unique integer ID. For grade changes and removals, lookup should be by ID. The printout should be sorted by last name. If two students have the same last name, then use the first name as a tie breaker. If the first names are also identical, then use the integer ID. Hint: Use two maps.

Data from Exercise E15.4

Write a program that keeps a map in which both keys and values are strings—the names of students and their course grades. Prompt the user of the program to add or remove students, to modify grades, or to print all grades. The printout should be sorted by name and formatted like this:

Carl: B+
Joe: C
Sarah: A