Consider the following UML diagram: remove $()$ should remove a customer from the list. If the customer is not present, the

operation should return false, otherwise it should remove the customer and return

true.

findByID $()$ should return a customer that has the provided ID$.$ If the list contains no

customer with that ID$,$ the operation should return the null pointer.

findByName $()$ should return a list of customers that have the provided name. If no

customers have that name, it should return an empty list.

findByDPC $()$ should return a list of customers that have the provided postal code in

their delivery address. If no customers have that code, it should return an empty list.

As specified in the diagram, the CustomerList class must inherit from QList. To

implement its member functions, one could search through the QList using a linear

search, but this would be very inefficient. A better way would be to maintain a number

of indices in the form of an associative container $($like a QMap, QHash, QMultiMap or

QMultiHash$)$ to provide fast lookups. In particular: Use an associative container to store pointers to customers with their IDs as keys,

to allow a customer with a particular ID to be found quickly.

Use an associative container to store pointers to customers with their names as

keys, to allow customers with a particular name to be found quickly.

Use an associative container to store pointers to customers with the postal codes

of their delivery addresses as keys, to allow customers with a particular code to be

found quickly.

Note that the pointers in these associative containers should point to the existing

Customers in the QList, not to copies of the customers. These containers should

be defined as private data members of the customerList class. Then the member

functions of CustomerList should do the following:

findByID$(),$ findByName$()$ and findByDPC$()$ should use the relevant

indexing container to find and extract the required information.

add $()$ should use findByID $()$ to check whether the ID is unique. If so$,$ it must

append the customer to the list and also update the three indexing containers.

remove $()$ should find and remove a specified customer. It also needs to update

the three indexing containers, and deallocate the memory used for the customer.

Write a console application to test all these functions. The program should add at least

$10$ customers to a list and then generate and display the result of searching for

customers with a particular ID$,$ a particular name and a particular postal code entered

from the keyboard.

We have provided the definition and implementation of a RandomCustomerFactory

class in the Additional Resources folder for COS$2614,$ which will generate random

Customers that can be stored in the customerList. $($This will save you $-$ and us $-$

from having to type in the details of $10$ customers to be stored in the list when testing

your program.$)$ You should use this class as part of your project.

The customer class is as defined follows:

Customer

$-$m$\_$Name : QString

$-$m$\_$CellNum : QString

m$\_$Address : QStringList

Customer$()$

Customer$($name: QString, cell : QString, addr : QStringList$))$

toString$($labelled : bool$)$: QString

The operations of the customerList class are intended to do the following:

add $()$ should append a customer to the list. However, it must first check whether the

ID of the customer is unique by searching for it in the customers already in the list. If

another customer has the same ID$,$ the operation should return false and terminate

without adding the new customer. Otherwise it should append the customer to the end

of the list and return true.