Question

Define a class template called genericStack for storing any data type in a static stack. Your class template must include a constructor, a destructor, push, pop, peek, isFull, and isEmpty functions (no display function is required). Write a simple main function in your program that demonstrates the class template with a stack of strings.

Answer 1

#include <iostream>
using namespace std;

// Class for stack
template <class ItemType>
class genericStack{
       private:
       ItemType *info;
       int top;

   public:
       genericStack();
       bool isEmpty();
       bool isFull();
       void push(ItemType x);
       void pop(ItemType &x);
       // destructor
       ~genericStack();
};

// Constructor to initialize stack
template <class ItemType>
genericStack<ItemType>::genericStack()
{
   info = new ItemType[5]; // set 5 as max
   top = -1; // assign -1 to first element
}
// Utility function to check if the stack is empty or not
template <class ItemType>
bool genericStack<ItemType>::isEmpty()
{
   return top == -1; // true for empty
}
// Utility function to check if the stack is full or not
template <class ItemType>
bool genericStack<ItemType>::isFull()
{
   return top == 5 ;   // top become size
}
// function to add an element x in the stack
template <class ItemType>
void genericStack<ItemType>::push(ItemType x)
{
   if (isFull())
   {
       cout << "Stack is Full.\n";
       return;
   }
   info[++top] = x; // push item to stack
}
// function to pop top element from the stack
template <class ItemType>
void genericStack<ItemType>::pop(ItemType &x)
{
   // check for stack underflow
   if (isEmpty())
   {
       cout << "UnderFlow Stack is Empty \n";
       return;
   }
   // // decrease stack size by 1 and copy to x
   x = info[top];
   top = top - 1;
}
// Destructor
template <class ItemType>
genericStack<ItemType>::~genericStack(){
   delete [] info; // delete stack
}
int main(){
   genericStack<string>obj; // create object of string
   string elem; // to get popped element
   // pushing
   obj.push("Ram");
   obj.push("albert");
   obj.push("newton");
   obj.pop(elem);
   cout<<elem<<endl; // newton since last in first out
   obj.pop(elem);
   cout<<elem<<endl;
   obj.pop(elem);
   cout<<elem<<endl;
}

/* OUTPUT */