Utilizing the code from Lab $4\mathrm{.}2,$ replace your Cargo class with a new base class. This will be the base for two classes

created through inheritance. The rewritten Cargo class will need to have a pure virtual function to have it redefined in

the child classes. This means that the Cargo class will become an abstract class. You will be able to use many parts of

the new Cargo class in the child classes since they will have the same arguments$/$parameters and the same functionality.

Child class Boeing$737$ will have the information for our $737$ aircraft, with the addition of maxload.

Unit and type: Container, Pallet or Combo Flat: AYF, AYK, AAA, AYY Containers, PAG, PMC$,$ PLA Pallets or CFE, CFK$,$ CFM

Combo Flats.

Maxload: $737$ max load is $46000$ pounds

Child class Boeing$767$ will have the information for our new $767$ aircraft, which has the following specifications:

Unit and type: Container, Pallet or Combo Flat: AKE, APE, AKC, AQP, AQF, AAP Containers, P$1$P$,$ P$6$P Pallets or CFQ$,$

CFX$,$ CFP Combo Flats.

Maxload: $767-300$ max load is $116000$ pounds

Change private to protected in the Cargo class only.

Create two classes which inherit from the Cargo class: Boeing$737$ and Boeing$767.$

Each class will need to inherit a default constructor, a copy constructor, a constructor that has six parameters and all the

getters and setters. Only one more function will be built in each class, the max weight function; all the rest will be

inherited.

The unit and type data are different for each class as is the aircraft type. Maxload is provided for both aircraft. Our $737$

can hold up to $46000$ pounds, and our $767$ can hold up to $116000$ pounds.

The main function needs to call the input function and do nothing else except return to end the program.

The data file lab$5$data.txt is provided in Canvas for your use. Your program will be tested with different data, but the

format Is guaranteed to be correct, and not to exceed $20$ lines.

In the input function loop read one line from the file each time through the loop, make sure that each piece of data is

valid; only Containers, Pallets and Combo Flat. Unit Load Abbreviations must agree with the plane type, the plane type

must be $737$ or $767,$ and weight must be within the limits for each plane. Look at the aircraft field in the record and call

the corresponding build function to build that type of unit. Ensure that the weight totals for both types of aircraft are

not exceeded by the units assigned to them. Check to ensure that another unit would not put them over the weight

limit$,$ if it would, then reject the unit and move on to the next unit in the file.

Store each unit object as a node in the appropriate linked list.

Once input has completed, you will have a number of objects of two different types stored in two different linked lists.

Use output to send the nodes to the screen, taking care to output all the $737$ nodes together, and all the $767$ nodes

together. Output the total weight of all the $737$ nodes and the total weight of all the $767$ nodes.

$*$ Use the lab$5$data.txt file which will contain data like

the following three lines of data; lab$5$data.txt will have no

more than $20$ lines of data

Pallet PAG PAG$45982$IB $7374978$ OAK

Container AYF AYF$23409$AA $7672209$ LAS

Combo Flat CFX CFX$89023$DL $7675932$ DFW

$*$ All weights are in pounds, don$$t worry about kilograms.

$*$ In the input function, declare an object of type ifstream named inputFile, which we will use to read from the file.

$*$ At the beginning of the code for the input function, open the file. If the open fails, tell the user that the file name is

not valid and give the user another opportunity to enter a correct file name..

$*$ In all other reads within the input function, remove the user prompt and read from the inputFile object, rather than

reading from the stdin object; that is$,$ use $>>.$

This is good code for reading data from a file and parsing the data into the

appropriate variables for use in object creation. You will want to use a try

block for exception handling to get a correct file name.

while$($getline$($inputFile$,$ cargostring$))///$read in one line of data, six or seven pieces

$\{$

istringstream cargoISS$($cargostring$)$; $///$place line in the input string stream

cargoISS $>>$ type$1$;

if $(($type$1.$compare$("$Combo$"))==0)///$looking for Combo

$\{$

cargoISS $>>$ type$2>>$ abrv $>>$ uld $>>$ plane $>>$ weight $>>$ dest;$///$seven pieces of data

type$1=$ type$1+""+$ type$2$;$///$valid Combo Flat, maybe

$\}$

else

$\{$

cargoISS $>>$ abrv $>>$ uld $>>$ plane $>>$ weight $>>$ dest;$///$six pieces of data

$\}$