#include
#include
using namespace std;
struct node
{
int item;
node *next;
};
class Stack
{
private:
node *top;
public:
Stack();
Stack(Stack&);
Stack& operator=(Stack&);
void push(int);
void pop();
int peek();
void reverse();
~Stack();
};
Stack::Stack()
{
top = NULL;
}
Stack::Stack(Stack &s)
{
s.reverse();
node *t = s.top;
while(t)
{
push(t->item);
t = t->next;
}
s.reverse();
}
Stack& Stack::operator=(Stack& s)
{
if(top != NULL)
{
while(top)
pop();
}
s.reverse();
node *t = s.top;
while(t)
{
push(t->item);
t = t->next;
}
s.reverse();
return *this;
}
void Stack::push(int data)
{
node *n = new node;
n->item = data;
n->next = top;
top = n;
}
int Stack::peek()
{
if(top==NULL)
cout<<"Stack Underflow";
else
return top->item;
}
void Stack::pop()
{
if(top != NULL)
{
node *r = top;
top = top->next;
delete r;
}
}
void Stack::reverse()
{
Stack s1;
while(top)
{
s1.push(peek());
pop();
}
top = s1.top;
s1.top = NULL;
}
Stack::~Stack()
{
while(top)
pop();
}