Write the C$++$ implementation of the pop member function of the Stack class:

pop$()$: deletes the value at the top of the stack and returns it$.$ Assume the stack is not empty $($no need to check$).$

The push function is given.

Write code in main$()$ to test this function. Write a loop to enter an unknown number of strings, one string per line. The loop stops when you enter $0.$ As you are entering strings, they are to be pushed onto a stack. Once done, pop them out of the stack and display them one per line.

Ex$.$: If the user enters

one

two

three

$0$

the output should be:

three

two

one

Ex$.$: If the user enters $0$ the output should be:

Empty stack!

$/**$~$*$~$*$~$*$

CIS $22$C

Project: Stack of strings $($pop$)$

Written by:

IDE:

$*$~$*/$

#include

#include

using namespace std;

class Stack$\_$str

$\{$

private:

$//$ Structure for the stack nodes

struct StackNode $\{$

string value; $//$ Value in the node

StackNode $*$next; $//$ Pointer to next node

$\}$;

StackNode $*$top; $//$ Pointer to the stack top

int length;

public:

Stack$\_$str$()\{$ top $=$ NULL; length $=0$; $\}//$Constructor

$//$ ~Stack$\_$str$()$; $//$ Destructor

$//$ Stack operations

bool isEmpty$()$; $/*$ Write your code here $*/$

bool push$($string$)$;

string pop$()$;

string peek$()$;

int getLength$()$;

$\}$;

$/**$~$*$~$*$~$*$

Member function push: pushes the argument onto the stack.

$*$~$**/$

bool Stack$\_$str::push$($string item$)$

$\{$

StackNode $*$newNode; $//$ Pointer to a new node

$//$ Allocate a new node and store num there.

newNode $=$ new StackNode;

if $(!$newNode$)$

return false;

newNode$->$value $=$ item;

$//$ Update links and counter

newNode$->$next $=$ top;

top $=$ newNode;

length$++$;

return true;

$\}$

$/**$~$*$~$*$~$*$

Member function pop pops the value at the top

of the stack off, and returns it

Assume stack is not empty

$*$~$**/$

$/*$ Define the pop function $*/$

int main$()\{$

Stack$\_$str s;

string item;

$/*$ Write your code here to test the push and pop functions $*/$

return $0$;

$\}$