Stack in C++

#include<iostream.h>

#include<conio.h>

int max=7;

int t=0;



class stack

{

                int s[7];

              public:

             void push(int);

            void pop();

            void top();

           void empty();

            void show();

};


void stack::push(int y) //Push Operation

{

if(t<max)

 {

  t=t+1;

  s[t]=y;

 }

else

cout<<endl<<"stack overflows..."<<endl;

}


void stack::pop() //Pop Operation

{

int item;

if(t>=0)

 {

  t=t-1;

  item=s[t+1];

  cout<<endl<<"popped item >>"<<item<<endl;

 }

 else

 cout<<endl<<"stack underflows"<<endl;

}



void stack::top() //To find the top of the stack

{

if(t>=0)

cout<<endl<<"topmost element >> "<<s[t]<<endl;

else

cout<<endl<<"stack underflows..."<<endl;

}


void stack::empty() //To check if the stack is empty

{

if(t<0)

cout<<endl<<"stack is empty..."<<endl;

else

cout<<endl<<"stack is not empty..."<<endl;

}


void main()

{

int a,x;

stack s1;

clrscr();

do

{

cout<<"enter an option..."<<endl<<"1-push"<<endl<<"2-pop"<<endl<<"3-top"<<endl<<"4-empty"<<endl;

cout<<"5-end"<<endl;

cin>>a;

cout<<endl;

switch(a)

{

case 1:

{

cout<<endl<<"enter a value  >> "<<endl;

cin>>x;

s1.push(x);

}

break;

case 2:

s1.pop();

break;

case 3:

s1.top();

break;

case 4:

s1.empty();

break;

}

}

while(a!=5);

getch();

}