In project$2,$ you defined the following two classes:

$//$ ShoppingCart.h

template

class ShoppingCart:public Bag $\{$

private:

double totalPrice;

public:

ShoppingCart$()$;

double getTotalPrice$()$const;

bool remove$($const ItemType& anEntry$)$;

bool add$($const ItemType& newEntry$)$;

$\}$;

$//$ Item.h

class Item

$\{$

private:

std::string name; $//$ name of the item

int quantity; $//$ quantity of the item

float price; $//$ price of the item

public:

Item$()$;

Item$($std::string name, float price, int qtty$)$;

void setName$($std::string name$)$;

void setQuatity$($int qtty$)$;

void setPrice$($float price$)$;

std::string getName$()$ const;

int getQuantity$()$ const;

float getPrice$()$ const;

friend std::istream &operator$>>($std::istream &ins, Item &target$)$;

$\}$;

std::ostream &operator$<<($std::ostream &out, const Item &target$)$;

bool operator $==($const Item& ob$1,$ const Item& ob$2)$;

In Project$2,$ the add member function allows duplicated items. For example, suppose the shopping cart currently contains the following items

$-------------------------------------------------$

Name Unit$\_$Price Quantity

T$-$shirt $$19\mathrm{.}992$

Sweater $$39\mathrm{.}991$

The total charge is $$79\mathrm{.}97$

$--------------------------------------------------$

If we add a new item as follows:

T$-$shirt $$19\mathrm{.}993$

the shopping cart becomes like this:

$-------------------------------------------------$

Name Unit$\_$Price Quantity

T$-$shirt $$19\mathrm{.}992$

Sweater $$39\mathrm{.}991$

T$-$shirt $$19\mathrm{.}993$

The total charge is $$139\mathrm{.}94$

$--------------------------------------------------$

Two T$-$shirt items are considered duplicated items although their quantities are different $($In Project $2$ we ignore the quantity when defining operator $==).$

Let's redefine the add member function to avoid duplicated items by only changing the quantity if the new item already exists. In above example, after adding the new item $"$T$-$shirt $$19\mathrm{.}993",$ the shopping cart should look like this:

$-------------------------------------------------$

Name Unit$\_$Price Quantity

T$-$shirt $$19\mathrm{.}995$

Sweater $$39\mathrm{.}991$

The total charge is $$139\mathrm{.}94$

$--------------------------------------------------$

To implement this new add function, first check if this newEntry is in the cart, and then perform the following two logic steps according to the checked results:

if this newEntry is not a duplicated item, simply add it to the cart. Then update the totalPrice;

otherwise, find the duplicated item from the cart and add its quantity to the new newEntry's quantity. Then remove the duplicated item from the cart; add the modified newEntry to the cart; and update the totalPrice.

Answer the following two questions about redefining the add function.

Question $6(5$ points$)$

For step $1),$ which of the following implementations is correct?

Question $6$ options:

a$)$

if$(!$contains$($newEntry$)$

$\{$

bool flag $=$ add$($newEntry$)$;

if$($flag$)$

totalPrice$+=$newEntry.getQuantity$()*$newEntry$.$getPrice$()$;

$\}$

b$)$

If$(!$contains$($newEntry$))$

$\{$

bool flag $=$ add$($newEntry$)$;

if$($flag$)$

totalPrice$+=$ newEntry.getPrice$()$;

$\}$

c$)$

if$(!$contains$($newEntry$))$

$\{$

bool flag $=$ Bag::add$($newEntry$)$;

if$($flag$)$

totalPrice $=2*$ totalPrice;

$\}$

d$)$

If$(!$contains$($newEntry$))$

$\{$

bool flag $=$ Bag::add$($newEntry$)$;

if$($flag$)$

totalPrice$+=$newEntry.getQuantity$()*$newEntry$.$getPrice$()$;

$\}$

Question $7(5$ points$)$

For step $2),$ which of the following implementations is correct?

Question $7$ options:

a$)$

vector items $=$ toVector$()$;

int numItems $=$ items.size$()$;

int q$\_$current;

int q$\_$new $=$ newEntry.getQuantity$()$;

for$($int i$=0$; i$<$ numItems; $++$i$)$

$\{$

if$($items$[$i$]==$newEntry$)\{$

q$\_$current$=$items$[$i$].$getQuantity$()$;

items$[$i$].$setQuantity $*($q$\_$current$+$q$\_$new$)$;

remove $($items$[$i$])$;

break;

$\}$

bool flag $=$ add$($newEntry$)$;

if$($flag$)$

totalPrice$+=$q$\_$new $*$ newEntry.getPrice$()$;

b$)$

int numItems $=$ getCurrentSize$()$;

int q$\_$current;

int q$\_$new $=$ newEntry.getQuantity$()$;

for$($int i$=0$; i$<$ numItems; $++$i$)$

$\{$

if$($items$[$i$]==$newEntry$)\{$

q$\_$current$=$items$[$i$].$getQuantity$()$;

newEntry.setQuantity$($q$\_$new$+$q$\_$current$)$;

remove$($items$[$i$])$;

break;

$\}$

$\}$

bool flag $=$ Bag::add$($newEntry$)$;

if $($flag$)$

totalPrice$+=$q$\_$new $*$ newEntry.getPrice$()$;

c$)$

vector items $=$ toVector$()$;

int numItems $=$ items.size$()$;

int q$\_$current;

int q$\_$new $=$ newEntry.quantity;

for$($int i$=0$; i$<$ numItems; $++$i$)$

$\{$