Objective: Practice using pointers and sort and search.

Write a menu$-$driven application that stores an inventory in an array of structs and lets a user print inventory sorted in descending order and unsorted original order.

Specifications$/$Requirements:

Inventory Item:

Item ID $-10$ digit

name $($one word$)$

quantity

price

main$()$

Main Menu

Print items in the original order

Sort menu option with a submenu to sort by any field $($Id$,$ name, quantity, and price$)$

use enum and switch to implement menus

if you are not familiar with enum, please see the textbook

it is better to use an enum class rather than an enum, but you have never used enum before, start with enum; enum has a simpler syntax

a user should be able to printed unsorted and sorted inventory as many times as a user wants

load records from an input file of unknown length

no record validation is needed

General Notes$/$Tips:

no vectors

thoroughly test your code

sorting

sorting using pointers is faster because you have to swap pointers only rather than the entire record. As you know, a pointer is usually stored in $4$ bytes

a submenu must have the option to go back to the previous menu or main menu. If a user got into a submenu by mistake, a user should be able to go back without executing other menu choices; for example, if a user entered the Sort submenu, a user should be able to go back to the previous menu or main without being forced to sort

submenu should be implemented as a switch with enum; let it fall through

write a sort menu outer$/"$wrapper$"$ function to

ask a user for the sort key

call the sort function, and then

call the print function

this way you'll have reusable sort and print functions; do not print from the sort function $-$ just because you need to sort it does not mean you want to print the result$-$ for example, if you want to use binary search, you need to have your array sorted$)$

actual sort function$/"$inner$"$

write one function to sort by any field

use Bubble Sort; it is not the most effective but the easiest to modify

do not copy and paste sort code multiple times into the same function

analyze the sort code, what would be different when you sort by balance vs by name?

string class lets you compare strings as you would compare numbers $($str$1>$str$2)$; "Adam"$>$"Adams" $->$false ; "Adam" $>$ "Ben" $->$ false ; "may"$>$"May" $->$ true $(\text{'}$m$\text{'}$ has higher ASCII value than $\text{'}$M$\text{'})$

do not write or use the swap function to swap pointers $-$ sort does an enormous number of swaps and executing a function is a computational expense. It takes $3-4$ statements to swap pointers, do it in the sort function directly

Code Snippets:

enum SortOption $\{$ID$=1,$ PRICE,NAME, BACK$\_$TO$\_$MAIN$\}//$enum TYPE declaration, it is not a variable

int sortOption$=0$;

cin$>>$sortOption;

switch$($sortOption$)\{$

case ID:

case PRICE:

case NAME: sortInventory $($pInventory$,$ numRecs, sortOption$)$ ; break;

case BACK$\_$TO$\_$MAIN $<<$"Going back to the main menu"; break;

default: cout$<<"$ Invalid choice. Try again"$<$