SQL with Manoj

Q26. Program to implement Generic classes for maintaining Stack:

Implement Stacks using generic classes with member functions PUSH, POP and DISPLAY. The Program should show implementation of Stack class with at least three different objects.

… from College notes (BCA/MCA assignments):

#include <iostream.h>
#include <conio.h>
#include <stdlib.h>

template <class T>
class Cstack{
	private:
		T arr[10];
		int ptr;
	public:
		void init(){
			ptr = -1;
			}
		void push(T, int);
		T pop(int &);
		void clear();
		void display(int);
	};

template <class T>
void Cstack<T> :: push(T elm_push, int t_ptr){
	if(t_ptr >= 9)
		cout<<"\n STACK OVERFLOW.";
	else
		arr[++t_ptr] = elm_push;
	}

template <class T>
T Cstack<T> :: pop(int &t_ptr){
	T elm_pop;
	if(t_ptr <= -1)
		cout<<"\n STACK UNDERFLOW.";
	else{
		elm_pop = arr[t_ptr--];
		cout<<"\n POPPED value is : "<<elm_pop;
		return elm_pop;
		}
	return 0;
	}

template <class T>
void Cstack<T> :: clear(){
	ptr = -1;
	cout<<"\n STACK Cleared.";
	}

template <class T>
void Cstack<T> :: display(int t_ptr){
	cout<<"\n STACK: ";
	if(t_ptr == -1)
		cout<<" Empty";
	else
		for(int i=0; i<=t_ptr; i++)
			cout<<arr[i]<<" ";
	}

int _menu(){
	int _ch;
	cout<<"\n STACK Type:- \n";
	cout<<"\n 1 -> Integer.";
	cout<<"\n 2 -> Float.";
	cout<<"\n 3 -> Character.";
	cout<<"\n Enter your choice: ";
	cin>>_ch;
	return (_ch);
	}

void main(){
	int ch, i_ptr = -1, f_ptr = -1, c_ptr = -1;
	int i_num;
	float f_num;
	char c_num;
	Cstack<int> Oint;
	Cstack<float> Ofloat;
	Cstack<char> Ochar;
	Oint.init();
	while(1){
		clrscr();
		cout<<"\n STACK - OPERATION";
		cout<<"\n ~~~~~~~~~~~~~~~~~ \n";
		cout<<"\n 1 -> PUSH";
		cout<<"\n 2 -> POP";
		cout<<"\n 3 -> CLEAR";
		cout<<"\n 4 -> DISPLAY";
		cout<<"\n 5 -> EXIT";
		cout<<"\n Enter your choice: ";
		cin>>ch;
		switch(ch){
			case 1:	// PUSH
				ch = _menu();
				switch(ch){
					case 1:
						cout<<"\n Enter an Integer Value 
  to push: ";
						cin>>i_num;
						Oint.push(i_num, i_ptr);
						i_ptr++;
						break;
					case 2:
						cout<<"\n Enter a Float Value to 
  push: ";
						cin>>f_num;
						Ofloat.push(f_num, f_ptr);
						f_ptr++;
						break;
					case 3:
						cout<<"\n Enter a Character to 
  push: ";
						cin>>c_num;
						Oint.push(c_num, c_ptr);
						c_ptr++;
						break;
					default:
						cout<<"\n Wrong Choice. No 
  Operation Done.";
					}
				break;
			case 2: // POP
				ch = _menu();
				switch(ch){
					case 1:
						Oint.pop(i_ptr);
						i_ptr--;
						break;
					case 2:
						Ofloat.pop(f_ptr);
						f_ptr--;
						break;
					case 3:
						Ochar.pop(c_ptr);
						c_ptr--;
						break;
					default:
						cout<<"\n Wrong Choice. No 
  Operation Done.";
					}
				break;
			case 3: // CLEAR
				ch = _menu();
				switch(ch){
					case 1:
						Oint.clear();
						i_ptr = -1;
						break;
					case 2:
						Ofloat.clear();
						c_ptr = -1;
						break;
					case 3:
						Ochar.clear();
						c_ptr = -1;
						break;
					default:
						cout<<"\n Wrong Choice. No 
  Operation Done.";
					}
				break;
			case 4: // DISPLAY
				cout<<"\n\n Integer Stack:-";
				Oint.display(i_ptr);
				cout<<"\n\n Float Stack:-";
				Ofloat.display(f_ptr);
				cout<<"\n\n Character Stack:-";
				Ochar.display(c_ptr);
				break;
			case 5: // EXIT
				cout<<"\n\n You chose to EXIT";
				getch();
				exit(1);
			default:
				cout<<"\n\n Enter an appropriate choice.";
			} // end of switch.
		getch();
		} // end of while.
	}// end of main.

Output:

STACK – OPERATION

1 -> PUSH
2 -> POP
3 -> CLEAR
4 -> DISPLAY
5 -> EXIT
Enter your choice: 1

STACK Type:-

1 -> Integer.
2 -> Float.
3 -> Character.
Enter your choice: 1

Enter an Integer Value to push: 43

STACK – OPERATION

1 -> PUSH
2 -> POP
3 -> CLEAR
4 -> DISPLAY
5 -> EXIT
Enter your choice: 4

Integer Stack:-
STACK: 43 119 23

Float Stack:-
STACK: 34.549999 78.900002

Character Stack:-
STACK: a n r