stack.cpp

#include<bits/stdc++.h>
using namespace std;
template<typename T>
struct linkedlist
{
    T data;
    linkedlist *next;
};


template<typename T>
class Stack
{
    T data;
    linkedlist<T> *root;
    int Size;
public:
    Stack()
    {

        root=NULL;

        Size=0;
    }
    void push(T data)
    {
        Size++;
        if(root==NULL)
        {

            root=new linkedlist<T>;
            root->data=data;

            root->next=NULL;
            return;
        }



        linkedlist<T> *temp=new linkedlist<T>;
        temp->data=data;
        temp->next=root;
        root=temp;
    }
    T  pop()
    {
        if(root==NULL)
        {
            cout<<"UNDERFLOW\n";
            return INT_MIN;
        }
        else if(root->next==NULL)
        {
            T x=root->data;
            Size--;
            root=NULL;
            return x;
        }
        else
        {
            T x=root->data;
            Size--;
            root=root->next;
            return x;
        }
    }
    T top(){
    return root->data;
    }
    int size()
    {
        return Size;
    }
    void print()
    {

    linkedlist<T> *c_node=root;

    while(c_node!=NULL)
    {

        cout<<c_node->data<<" ";
        c_node=c_node->next;
    }
    cout<<endl;
    }

};
int main()
{
    Stack<int> s;
    s.push(3);
    //s.print();

    s.push(43);
    // s.print();

    s.push(31);
    // s.print();
cout<<s.top()<<endl;
     s.print();
     s.pop();
     s.print();
     s.pop();
     s.print();
}