Question

Description( IN C++)!!

The purpose of this challenge is to implement a stack using a Linked List as a backing data structure

Requirements

1. Write the following structs

   struct Location
   {
     string name;
     string address;
   };
   
   struct VisitNode
   {
     Location loc;
     VisitNode * next;
   };

2. Create a class called Stack. In this class, create a private variable VisitNode * head. This will keep track of the location of the head node.
3. Add the following private function. This function will be used to dynamically create new nodes for the linked list.

   VisitNode * create()
   {
     VisitNode * newnode;
     try
     {
       newnode = new VisitNode;
     }
     catch (bad_alloc)
     {
       newnode = NULL;
     }
     return newnode;
   }
   
   // USAGE: To create a new node, use as follows
   // VisitNode * newnode = create();

4. Create a private function called void deallocate(). This function will traverse the entire list and delete each node. Remember to make a copy of head. Also, realize that if you delete the current node as you’re traversing, you may lose the reference to the next node.
5. Create a destructor which will call deallocate() and set head to NULL.
6. Create a public function, bool push(string name, string address). This function will:
   1. create a new node (VisitNode) using the create() function you wrote earlier. The new node will be assigned the values for loc from the function’s parameter values.
   2. add the new node to the front of the linked list (where head points). Remember to deal with two possible scenarios: 1) The list is still empty and this is the first node to be added and 2) The list is not empty
   3. point head to the newly-added node
   4. return true if it’s successful, and false otherwise. The only reason it would be false is if the new node didn’t get created by the create() function (if the new node is NULL)
7. Create a public function, string pop(). This function will
   1. Identify the node at the front of the list (if not empty)
   2. Copy the value of the node’s loc.name property into a temporary variable
   3. Point head to the next node in the list (or NULL if it’s the last node)
   4. delete the first node (this effectively is the “pop” action)
   5. Return the loc.name value stored in the temporary variable. Return a blank string if the linked list is empty
8. Create a friend function void show(Stack & S). This will display all the loc.name values of all the nodes on a single line, separated by spaces. Traverse the entire linked list to show the node values.
9. main() is given below. Use it exactly as is. Note that main uses the Stack class as an abstract data type (ADT). From the perspective of the object browser, it doesn’t even know or care that a linked-list is the mechanism that makes LIFO (last-in, first-out) work.

Sample main()

int main()
{
  Stack browser;

  // simulate a browser history
  browser.push("Google", "https://google.com");
  browser.push("Amazon", "https://amazon.com");
  browser.push("LinkedIn", "https://LinkedIn.com");
  browser.push("Reddit", "https://reddit.com");  

  show(browser);   // this should show the entire history

  // simulate clicking Back button
  string top = browser.pop();
  if (top != "")
    cout << endl << "Clicked back from " << top << endl;
  show(browser);

  // simulate clicking Back button  
  top = browser.pop();
  if (top != "")
    cout << endl << "Clicked back from " << top << endl;
  show(browser);

  // simulate clicking Back button
  top = browser.pop();
  if (top != "")
    cout << endl << "Clicked back from " << top << endl;
  show(browser);

  return 0;
}

Answer 1

please please thumbs up!!!

hope it will help uh out!!

Code::
(IN C++ PROGRAMMING LANGUAGE)

-------------------------------------------------------

#include <iostream>
using namespace std;
struct Location{ // create structure to represent data in node
string name;
string address;
};

// create structure to represent node in linked list
struct VisitNode {
Location loc; // data stored in node
VisitNode* next; // pointer to next node
};

// create class to represent stack
class Stack {
private:
VisitNode* head; // top of the stack

// function to create new node
VisitNode* create() {
VisitNode* newNode;
try {
// dynamically allocte memory to new node
newNode = new VisitNode;
}
catch (bad_alloc) {
// if allocation fail set new node to NULL
newNode = NULL;
}
return newNode;
}

// delete all nodes from stack
void deallocate() {
// create a temparory node to delete current node
VisitNode* temp = head; // assign temp to head to delete top node
while (head != NULL) {
// move head to next node
head = head->next;
// delete current node
delete temp;
// re assign temp to head to delete next node
temp = head;
}
}

public:
// destructor
~Stack() {
deallocate();
head = NULL;
}

// place a new node on topof stack
bool push(string name, string address) {
// create a new node
VisitNode* newNode = create();
// check if newNode created, before addiing data to it
if (newNode == NULL) {
return false;
}
// add data to new node
newNode->loc.name = name;
newNode->loc.address = address;
newNode->next = NULL;
// now assign new node at top of stack
// check if stack have any nodes
if (head == NULL) {
// newNode is first node to be added
head = newNode;
}
else {
// assign newNode to top of head
newNode->next = head;
// re-assign head at top node
head = newNode;
}
}

// removes top node and returns name from loc data
// if stack is empty returns empty string
string pop() {
// check if stack is empty
if (head == NULL) {
// return empty string
return "";
}
else {
// copy the data from top node
string data = head->loc.name;
// create a temporary node to delete first node
VisitNode* temp = head;
// move head to next node in stack
head = head->next;
// delete the top node
delete temp;
return data;
}
}
// create a friend function
// friend function can access the private data of the class member
friend void show(Stack& s) {
// traverse the entire list and print each node's loc.name
// in sigle line
// to traverse the list create a pointer(iterator)
VisitNode* itr = s.head;
while (itr != NULL) { // loop till end of list
// print each node's data
cout << itr->loc.name << " ";
// move iterator to next node
itr = itr->next;
}
}
};

// main function as given
int main() {
Stack browser;
// simulate browser history
browser.push("Google", "https://google.com");
browser.push("Amazon", "https://amazon.com");
browser.push("LinkedIn", "https://LinkedIn.com");
browser.push("Reddit", "https://reddit.com");

show(browser); // this should show the entire history

// simulate clicking Back button
string top = browser.pop();
if (top != "") {
cout << endl << "Clicked back from " << top << endl;
}
show(browser);

// simulate clicking Back button
top = browser.pop();
if (top != "") {
cout << endl << "Clicked back from " << top << endl;
}
show(browser);
// simulate clicking Back button
top = browser.pop();
if (top != "") {
cout << endl << "Clicked back from " << top << endl;
}
show(browser);

return 0;
}
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output::