Question

I want to know 'Linked link + queue' and 'Linked link Stack' code in C++

But there is a condition. There shall be the following 'menu':

*****Menu*****

1. Insert into Stack 2. Insert into Queue

3. Delete from Stack 4. Delete from Queue

5. View Content in Stack 6. View Content in Queue

**********************************************

Let me give you a example.

>> 1 30 // Insert 30 into Stack

>>1 58// Insert 58 into Stack

>>1 26 // Insert 26 into Stack

>>3 // Delete from Stack

>>5 // View Content in Stack

Result: 58 30 ( Outputs in LIFO order)

Please help me. I am so curious.

Answer 1

#include <iostream>
using namespace std;
struct Node
{
  int data;
  Node *link;
};
Node *top = NULL;

bool isempty ()
{

  if (top == NULL)
    return true;
  else
    return false;
}

void insert_stack (int value)
{
  // Create new node temp and allocate memory  
  Node *ptr = new Node ();
  ptr->data = value;
  ptr->link = top;
  //// Make ptr as top of Stack  
  top = ptr;
}

void del_stack ()
{
  //check stack is empty or not
  if (isempty ())
    {
      cout << "Stack is empty";

    }
  else
    {
      Node *ptr = top;
      // Destroy connection between 
      // first and second  
      top = top->link;
      delete (ptr);
    }
}

void viewContent_stack ()
{
  struct Node *temp;

  // Check for stack underflow  
  if (isempty ())
    {
      cout << "\nStack Underflow";
      exit (1);
    }
  else
    {
      temp = top;
      cout << "Result:";
      while (temp != NULL)
        {

          // Print node data  
          cout << temp->data << " ";

          // Assign temp link to temp  
          temp = temp->link;
        }
    }
}



struct Qnode
{
  int qdata;
  Qnode *qlink;
};
Qnode *front = NULL;
Qnode *rear = NULL;
bool isqempty ()
{
  if (front == NULL && rear == NULL)
    {
      return true;
    }
  else
    return false;
}

void insert_queue (int value)
{

  //new node and ptr store its address 

  Qnode *ptr = new Qnode ();
  //put the value in data part 
  ptr->qdata = value;
  //make link is NULL
  ptr->qlink = NULL;


  //adjust front pointer
  if (front == NULL)
    {
      //it points to first node
      front = ptr;
      rear = ptr;
    }
  else
    {

      rear->qlink = ptr;

      rear = ptr;
    }


}

void del_queue ()
{

  if (isqempty ())
    cout << "Queue empty";
  else
    {
      if (front == rear)
        {
          //delete
          free (front);
          front = rear = NULL;
        }
      else
        {
          Qnode *ptr = front;
          front = front->qlink;
          free (ptr);
        }
    }


}

void viewContent_queue ()
{
  if (front == NULL)
    {
      cout << "queue Underflow." << endl;
      return;
    }
  Qnode *temp = front;
  cout << "Result:";
  //will check until NULL is not found
  while (temp)
    {
      cout << temp->qdata << " ";
      temp = temp->qlink;
    }
  cout << endl;


}






int main ()
{
  int c, num, flag = 1;
  cout<<"\n";
        cout << "*****Menu*****" << "\n";
  cout << "1. Insert into Stack  2. Insert into Queue\n";
  cout << "3. Delete from Stack 4. Delete from Queue \n";
  cout << "5. View Content in Stack 6. View Content in Queue \n";
  cout << "**********************************************\n";

  //read choice from the menu
  while (flag == 1)
    {
      cin >> c;
      if (c == 1)
        {
          cin >> num;
          insert_stack (num);
        }
      else if (c == 2)
        {
          cin >> num;
          insert_queue (num);
        }
      else if (c == 3)
        {
          del_stack ();

        }
      else if (c == 4)
        del_queue ();
      else if (c == 5)
        {
          viewContent_stack ();
          cout<<"\n";
        cout << "*****Menu*****" << "\n";
  cout << "1. Insert into Stack  2. Insert into Queue\n";
  cout << "3. Delete from Stack 4. Delete from Queue \n";
  cout << "5. View Content in Stack 6. View Content in Queue \n";
  cout << "**********************************************\n";

 
        }
      else if(c==6)
        {
          viewContent_queue ();

cout<<"\n";
        cout << "*****Menu*****" << "\n";
  cout << "1. Insert into Stack  2. Insert into Queue\n";
  cout << "3. Delete from Stack 4. Delete from Queue \n";
  cout << "5. View Content in Stack 6. View Content in Queue \n";
  cout << "**********************************************\n";
        }
        else{
            flag=0;
        }

    }
  return 0;
}

//screenshots for code:

Explanation:

1. In main, we are initializing flag is 1 when ever the flag is 1 the while condition is true
2. Executes menu option
3. when 1 clicked element is inserted into stack
4. when 2 clicked element is inserted into queue;
5. when option 3 is selected top of the element from stack is removed;
6. when option 4 is selected element will be removed from queue;
7. for option 5 stack elements will be deleted and for 6 queue elements will be displayed