Question

Can I get a C++ code and output for this program using classes instead of using struct. The following program implements a Last In First Out (LIFO) stack.

( I want to use class for function definitions too and if main need.)

#include <iostream>

using namespace std;

const int MAX = 100;

struct stack
{
   int s[MAX]; // an array of integers
   int top; // the index of the last number

};

void push(stack &, int);
void pop(stack&, int &);
int peek(stack);
void display(stack);

void main()
{
   stack s;
   s.top = -1;
   push(s, 2); // add 2 into the stack
   push(s, 5); // add 5 into the stack
   push(s, 1); // add 1 into the stack

   int num = peek(s); // look at the last number in the stack
   cout << "the top element is " << num << endl;

display(s); // output numbers of the stack from last to first

pop(s, num); // remove the last number from the stack

cout << "the remove element is " << num << endl;

   system("pause");

}
void push(stack &sta, int number)
{
   if (sta.top < MAX - 1)
   {
       sta.top++;
       sta.s[sta.top] = number;

   }

}
void pop(stack &sta, int &num)
{
   if (sta.top > -1)
   {
       num = sta.s[sta.top];
       sta.top--;

   }
}
int peek(stack sta)
{
   if (sta.top > -1)
       return sta.s[sta.top];

}
void display(stack sta)
{
   for (int i = sta.top; i > -1; i--)
   {
       cout << sta.s[i] << " ";
   }
   cout << endl;
}

Thanks!

Answer 1

The programming language C++ program using class is given below:

#include <iostream>

using namespace std;

const int MAX = 100;

class stack
{
//private data member
int s[MAX]; // an array of integers
int top; // the index of the last number
  
public:
//default constructor
//set the top value -1
stack()
{
top = -1;
}
void push(int number)
{
if (top < MAX - 1)
{
top++;
s[top] = number;
  
}
  
}
void pop(int &num)
{
if (top > -1)
{
num = s[top];
top--;
  
}
}
int peek()
{
if (top > -1)
return s[top];
  
}
void display()
{
for (int i = top; i > -1; i--)
{
cout << s[i] << " ";
}
cout << endl;
}
};

int main()
{
stack s;
//now data member top is private type
//but default constructor will set the top = -1
//s.top = -1;
s.push(2); // add 2 into the stack
s.push(5); // add 5 into the stack
s.push(1); // add 1 into the stack

int num = s.peek(); // look at the last number in the stack
cout << "the top element is " << num << endl;

s.display(); // output numbers of the stack from last to first

s.pop(num); // remove the last number from the stack

cout << "the remove element is " << num << endl;

system("pause");
return 0;

}

OUTPUT: