stac

import java.util.Scanner;

public class stac{
    public static void main(String Args[])
    {
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter stack size : ");

        stack_maker st = new stack_maker(sc.nextInt());
        while(true)
        {
            System.out.println("\n1. Push\n2. Pop\n3. Peek\n4. Display\n5. New Stack\n6. Exit");
            System.out.print("\nEnter your choice : ");
            switch(sc.nextInt())
            {
                case 1:
                System.out.print("\n\tEnter no. to Push : ");
                st.Push(sc.nextInt());
                break;

                case 2:
                st.Pop();
                break;

                case 3:
                st.Peek();
                break;

                case 4:
                st.Display();
                break;

                case 5:
                System.out.print("\n\tThe prervios stack will be lost. Continue(y/n)?");
                if(sc.next().toLowerCase().charAt(0) == 'y')
                {
                    System.out.print("\n\tEnter new stack size : ");
                    st = new stack_maker(sc.nextInt());
                }
                break;


                case 6:
                st.finalize();
                return;
            }

            System.out.println();
        }
    }
}

class stack_maker {
    private int[] stack;
    private int top, size;

        stack_maker(int size)
        {
            top = -1;
            this.size = size;
            stack = new int[size];
            System.out.println("New stack of size "+ size +" created\n");
        }

        private boolean isFull()
        {
            if(top == size-1)
                return true;
            return false;
        }

        private boolean isEmpty()
        {
            if(top == -1)
                return true;
            return false;
        }

        public void Push(int n)
        {
            if(isFull())
            {
                System.out.println("\nStack Overflow!");
                return;
            }
            System.out.println("\n" + n + " added in stack");
            stack[++top] = n;
        }

        public void Pop()
        {
            if(isEmpty())
            {
                System.out.println("\nEmpty stack, can't pop!");
                return;
            }
            System.out.println("\n"+stack[top--]+ " was popped");
        }

        public void Peek()
        {
            if(isEmpty())
            {
                System.out.println("\nEmpty stack, can't peek!");
                return;
            }
            System.out.println("\nElement at the top is : " + stack[top]);

        }

        public void Display()
        {
            if(isEmpty())
            {
                System.out.println("\nEmpty Stack, nothing to display!");
                return;
            }
            System.out.println("\n\n");
            for(int i = top; i >= 0; i--)
                System.out.println("|\t"+stack[i]+"\t|\n-----------------");
        }

        protected void finalize()
        {
            System.out.println("BYE!");
            System.gc();
        }


}