C++ Program to Implement Stack in STL

Stack is a linear data structure which follows a particular order in which the operations are performed. The order may be FILO (First In first out) or LIFO (Last In First Out)

Algorithm

Begin
   Declare stack vector.
   Take the input as per choice.
   Call the functions within switch operation:
   s.size() = Returns the size of stack.
   s.push() = It is used to insert elements to the stack.
   s.pop() = To pop out the value from the stack.
   s.top() = Returns a reference to the top most element of stack.
End.

Example Code

#include <iostream>
#include <stack>
#include <string>
#include <cstdlib>
using namespace std;
int main() {
   stack<int> s;
   int c, i;
   while (1) {
      cout<<"1.Size of the Stack"<<endl;
      cout<<"2.Insert Element into the Stack"<<endl;
      cout<<"3.Delete Element from the Stack"<<endl;
      cout<<"4.Top Element of the Stack"<<endl;
      cout<<"5.Exit"<<endl;
      cout<<"Enter your Choice: ";
      cin>>c;
      switch(c) {
         case 1:
            cout<<"Size of the stack: ";
            cout<<s.size()<<endl;
         break;
         case 2:
            cout<<"Enter value to be inserted: ";
            cin>>i;
            s.push(i);
         break;
         case 3:
            i = s.top();
            if (!s.empty()) {
               s.pop();
               cout<<i<<" Deleted"<<endl;
            }else {
               cout<<"Stack is Empty"<<endl;
            }
         break;
         case 4:
            cout<<"Top Element of the Stack: ";
            cout<<s.top()<<endl;
            break;
         case 5:
            exit(1);
         break;
         default:
            cout<<"Wrong Choice"<<endl;
      }
   }
   return 0;
}

Output

1.Size of the Stack
2.Insert Element into the Stack
3.Delete Element from the Stack
4.Top Element of the Stack
5.Exit

Enter your Choice: 1
Size of the stack: 0
1.Size of the Stack
2.Insert Element into the Stack
3.Delete Element from the Stack
4.Top Element of the Stack
5.Exit

Enter your Choice: 2
Enter value to be inserted: 1
1.Size of the Stack
2.Insert Element into the Stack
3.Delete Element from the Stack
4.Top Element of the Stack
5.Exit

Enter your Choice: 2
Enter value to be inserted: 7
1.Size of the Stack
2.Insert Element into the Stack
3.Delete Element from the Stack
4.Top Element of the Stack
5.Exit

Enter your Choice: 2
Enter value to be inserted: 6
1.Size of the Stack
2.Insert Element into the Stack
3.Delete Element from the Stack
4.Top Element of the Stack
5.Exit

Enter your Choice: 2
Enter value to be inserted: 10
1.Size of the Stack
2.Insert Element into the Stack
3.Delete Element from the Stack
4.Top Element of the Stack
5.Exit

Enter your Choice: 2
Enter value to be inserted: 4
1.Size of the Stack
2.Insert Element into the Stack
3.Delete Element from the Stack
4.Top Element of the Stack
5.Exit

Enter your Choice: 1
Size of the stack: 5
1.Size of the Stack
2.Insert Element into the Stack
3.Delete Element from the Stack
4.Top Element of the Stack
5.Exit

Enter your Choice: 3
4 Deleted
1.Size of the Stack
2.Insert Element into the Stack
3.Delete Element from the Stack
4.Top Element of the Stack
5.Exit

Enter your Choice: 4
Top Element of the Stack: 10
1.Size of the Stack
2.Insert Element into the Stack
3.Delete Element from the Stack
4.Top Element of the Stack
5.Exit
Enter your Choice: 5

Exit code: 1