Question

Task 2: Implement stack with the help of single linked list. Make sure you follow LIFO pattern and implement push, pop, isempty, isfull and status functions in it. A maximum size of stack needs to be specified in order to implement isfull function.

You are required to submit 3 files, myfriends.h, myfriends.cpp, main.cpp

Answer 1

The code for the above program is given below, i have commented in line for the explanation.

myfriends.cpp

#include <iostream>
using namespace std;

int count=0;
int Max;

struct Node // struct for a node in linked list
{
int data;
struct Node* next;
};
struct Node* ptr=NULL;// pointer to the top of stack

void setSize(int n) // to set maximum size of the stack
{
Max=n;
}

bool isEmpty()// to check if stack is empty
{
if(ptr == NULL)// if pointer NULL it means the stack is empty
{
return true;
}
return false;
}

void status()
{
struct Node* temp; // temp pointer to traverse the stack
  
if(isEmpty()) // is stack is empty return empty
{
cout<<"\nThe stack is Empty!\n";
exit(1);
}
  
else{
temp = ptr; // start with the top of stack
while(temp!=NULL && count!=0)
{
cout<<temp->data<<" --> ";// print the data
temp= temp->next;// move down the stack
}
cout<<"NULL"<<endl;
  
}
}

bool isFull(int Max)
{
if(count==Max)// if count is equal to maximum size return true
{
return true;
}
return false;
}

void push(int data)// to push the element in stack
{
struct Node* temp = new Node();// create a new node
  
if(!isFull(Max))// if stack is not already full
{
temp->data = data;// add data to new node
temp->next = ptr;// next port of this node will point to p of the stack
ptr = temp;// top will change to new node
  
count++;// increment the counter to keep track of total node
}
else{// if stack is already full cant add
cout<<"Cant add stack is already full!"<<endl;
cout<<"Status till Know:\n";
status();// print the status till know
exit(1);
}
  
  
}

void pop()// to pop the element from the stack
{
struct Node* temp;// pointer to point to removed node to delete it
  
if(isEmpty())// if stack is empty cant delete
{
cout<<"\nThe stack is Empty!\n";
exit(1);
}
else{
temp = ptr;// point temp pointer to the top of stack
ptr = ptr->next; // change top pointer to next element of stack
temp->next = NULL;// delete the next part of the removed node
free(temp);// free the space of removed node
count--;// decrement counter
}
}

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

myfriends.h

void push(int data);
bool isEmpty();
bool isFull(int size);
void pop();
void status();
struct Node;
void setSize(int n);

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

main.cpp

#include <iostream>
#include "myfriends.h"

using namespace std;

int main()
{
  
int n;
cout<<"Maximum size of stack you want?";
cin>>n;
setSize(n);// set size of the stack
  
push(1);
push(2);
push(3);
push(4);
status();
pop();
pop();
cout<<"After 2 pop are called\n";
status();

return 0;
}

Output:-

Maximum size of stack you want?5 4 --> 3 --> 2 --> 1 --> NULL After 2 pop are called 2 --> 1 --> NULL ... Program finished with exit code 0 Press ENTER to exit console.

Hope it clears your doubt :) and you like it.