this is the code :

#include

#include

#include

#include

using namespace std;

class Node

{

public:

int data;

Node* next;

//Node * prev;

};

class Stack {

public:

void push(Node** head_ref, int new_data);

Node* pop(Node** head_ref);

void peek(Node** head_ref);

};

// inserting node at the begining of the list

// Node * head pointer

// Node **head pointer of pointer

void Stack::push(Node** head_ref, int new_data) {

if (*head_ref == NULL) {

Node* new_node = new Node(); // dynamic allocation of a new memeory // heap

new_node->data = new_data;

new_node->next = NULL;

(*head_ref) = new_node;

return;

}

else {

Node* new_node = new Node(); // dynamic allocation of a new memeory // heap

new_node->data = new_data;

new_node->next = (*head_ref);

(*head_ref) = new_node;

return;

}

}

// poping node at the begining of the Stack

Node* Stack::pop(Node** head_ref) {

if (*head_ref != NULL) {

Node* poped_node = (*head_ref);

(*head_ref) = (*head_ref)->next;

return poped_node;

}

else {

printf("Error cannot pop from an empty Stack");

return *head_ref;

}

}

string readfile(string filename) {

string line;

ifstream myfile(filename);

if (myfile.is_open()) {

while (getline(myfile, line)) {

cout

}

myfile.close();

return line;

}

else {

cout

return line;

}

}

// poping node at the begining of the Stack

void Stack::peek(Node** head_ref) {

if (*head_ref != NULL) {

printf("top item in stack is %d ", (*head_ref)->data);

}

else {

printf("Error cannot peek an empty Stack");

}

}

int main() {

Node* head = NULL;

Node* result = NULL;

Stack stack1;

stack1.push(&head, 6);

stack1.push(&head, 4);

stack1.push(&head, 3);

stack1.push(&head, 10);

stack1.push(&head, 11);

stack1.peek(&head);

result = stack1.pop(&head);

cout data

delete result;

stack1.peek(&head);

cout

system("PAUSE");

return 0;

}

Q1: In today's lecture, we saw how to implement Stack using linked list, based on that implement queue using linked list which include the following: 1) Write function to push (enqueue) an item into a queue, remember you need to use another pointer called tail in addition to head? 2) Write a function to pop (dequeue) an item from a queue? 3) Write a function to print items in the queue