stack using linked list.cpp

#include<iostream>
usingnamespacestd;

// Stack implementation using Linked List


// class for _stack
class_stack
{
// private data---->


// node structure
structnode
 {
int data;
 node* next;
 };
 node* head = NULL;
int n = 0;// for size of stack
public:
// public data---->


// push fuction
voidpush(int a) {
// making node 
 node* temp = newnode();
// check whether a stack overflows or not
if(temp==NULL){cout<<"Stack Overflow\n";return;}

// adding nodes at the beginning of linkked list
 temp->data = a;
 temp->next = head;
 head = temp;
 n++;// increamenting size
 }

// pop function
voidpop() {
// check stack is empty or not
if (head == NULL) {cout << "Empty stack\n"; return;}
// points temp node pointer to the top
 node *temp = head;
// move head to next node
 head = head->next;
// delete temp node pointer
delete(temp);
 n--;// decreamenting size
 }

// top function
inttop() {
// check stack is empty or not
if (head == NULL) {cout << "Empty stack"; return -1;}
// return top node data
return head->data;
 }

// stack emptly check function
boolisEmpty() {
if (head == NULL)returntrue;
elsereturnfalse;
 }

// function for returning the size of stack
intsize() { return n;}
};



intmain() {


 _stack s;

// user/random inputs..
for (int i = 0; i < 10; ++i) {int a; cin >> a; s.push(a); cout << s.top() << endl;}
 s.pop();
 s.pop();
 cout << s.isEmpty() << endl;
 cout << s.top() << endl;
 s.push(121);
 cout << s.top() << endl;
return0;
}