The program you wrote in Stacks $1$ is incomplete. Without a destructor it creates a memory leak. A destructor has been defined in this program but it is incorrect. To visualize how the destructor works, a cout statement has been added. Fix the errors, including the cout statement, to display the value in each node of the stack before releasing the memory.

Write a loop in main$()$ 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.

Ex$.$: If the user enters

one

two

three

$0$

the output $($from the destructor$)$ should be:

three $-$ deleted!

two $-$ deleted!

one $-$ deleted!

Empty stack!

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

Empty stack!

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

CIS $22$C

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

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; $//$ Number of nodes

public:

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

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

$//$ Stack operations

$//$ bool isEmpty$()$;

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 item there.

newNode $=$ new StackNode;

if $(!$newNode$)$

return false;

newNode$->$value $=$ item;

$//$ Update links and counter

newNode$->$next $=$ top;

top $=$ newNode;

length$++$;

return true;

$\}$

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

Destructor

$*$~$**/$

Stack$\_$str::~Stack$\_$str$()$

$\{$

StackNode $*$currNode;

$//$ Position nodePtr at the top of the stack.

currNode $=$ top;

$//$ Traverse the list deleting each node.

while $($currNode$)$

$\{$

cout $<<$ currNode$->$value $<<"-$ deleted!" $<<$ endl;

delete currNode;

currNode $=$ NULL;

currNode $=$ currNode$->$next;

$\}$

cout $<<$ "Empty stack!" $<<$ endl;

$\}$

int main$()\{$

Stack$\_$str s;

string item;

$/*$ Write your code here $*/$

return $0$;

$\}$