namespace Zasobnik
{
    public class Stack
    {
        private int[] data;
        private int head = -1;
        public static int defaultValue = int.MaxValue;
        private static int resizeFactor = 2;
        public Stack(uint initCapacity)
        {
            data = new int[initCapacity];
        }

        public int Size()
        {
            return head + 1;
        }

        public int Pop()
        {
            if (!IsEmpty())
            {
                int value = data[head]; // zjistíme prvek
                head--; // posuneme hlavu
                return value;
            }
            return defaultValue;
        }

        public int Peek()
        {
            if (!IsEmpty())
            {
                return data[head]; // pouze zjistíme prvek
            }
            return defaultValue;
        }

        public bool Push(int number)
        {
            int nextPos = ++head;
            if (nextPos >= data.Length)
            {
                ResizeDataStructure();
            }
            data[nextPos] = number;
            return true;
        }

        private void ResizeDataStructure()
        {
            int[] nextData = new int[data.Length * resizeFactor];
            data.CopyTo(nextData, 0);
            data = nextData;
        }

        private bool IsEmpty()
        {
            return head <= -1;
        }

        public void Print()
        {
            for (int i = Size() - 1; i >= 0; i--)
            {
                Console.Write(data[i]);
                Console.Write(", ");
            }
            Console.WriteLine();
        }


    }
}


using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Zasobnik
{
    public class Stack
    {
        private class ListNode
        {
            public int value;
            public ListNode next = null;

            public ListNode(int val, ListNode next)
            {
                this.value = val;
                this.next = next;
            }
        }


        private ListNode headNode = null;
        private int size = 0;

        private static int defaultValue = int.MaxValue;
        public Stack(uint initCapacity)
        {

        }

        public int Size()
        {
            return size;
        }

        public int Pop()
        {
            if (!IsEmpty())
            {
                int value = headNode.value; // zjistíme prvek
                headNode = headNode.next; // posuneme hlavu
                size--; // úprava velikosti
                return value;
            }
            return defaultValue;
        }

        public int Peek()
        {
            if (!IsEmpty())
            {
                return headNode.value; // pouze zjistíme prvek
            }
            return defaultValue;
        }

        public bool Push(int number)
        {
            ListNode newHead = new ListNode(number, headNode);
            headNode = newHead;
            size++;
            return true;
        }


        private bool IsEmpty()
        {
            return headNode == null;
        }

        public void Print()
        {
            ListNode node = headNode;
            while (node != null) {
                Console.Write(node.value);
                Console.Write(",");
                node = node.next;
            }
            Console.WriteLine();
        }


    }
}