JAVA question

create a class Cost, that tracks the cost of items. Within Cost, create a public inner (non-static) class, Item, that includes the following:

public class Item { String name; int cost; // in cents public Item(String n, int c) { name = n; cost = c; } public String toString() { return name + " " + cost; } }

Modify your inner Item class so that it implements the Comparable interface. Items should be ordered based on the cost (lowest cost first). If two items cost the same amount then order these items alphabetically based on their name. Add an instance data structure (HashMap) to your Cost class for storing items, using the item's name as the key. Add an instance method void addItem(String name, int cost) to your Cost class that allows new items to be added, and a method printCost() that prints out all items sorted in the order described above, one item per line, with a single space separating the item name and its cost. Suppose you are given a gift voucher for the above shop. Assume that the shop does not give change on gift vouchers, and you do not wish to spend any more than what is in the gift voucher. Add an instance method int voucherWaste(int value) to Cost which will return the difference between the value of the voucher (in cents) and what could be spent given the set of items in the shop. e.g. Say you had a voucher for $100 and the items in the shop were worth: $87, $20, $99, $12, then the most you could spend would be the full $100 (just buy 5 of the $20 item) so there would be zero waste, whereas, if the items in the shop were worth: $87, $22, $30, $45 then the most you could spend would be $97 (remember that your method will express the voucher and the costs in the same units, cents).