MyQueue

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

namespace CustomQueue
{
    public class MyQueue <T>
    {
        private T[] _items;
        private int head, tail;
        public int Count { get; private set; }
        private int _capacity;

        public MyQueue()
        {
            _capacity = 4;
            _items = new T[_capacity];
            head = 0; tail = 0;
            Count = 0;
        }
        #region Methods
        /// In Process:
        /// Ready: Push(), Pop(), Peek(), Count, Contains();
        public void Push(T item)
        {
            if(Count == _capacity)
            {
                ExpandedCapacityQueue();
            }
            _items[tail % _capacity] = item;
            tail++; Count++;
        }
        public T Pop()
        {
            if(Count == 0)
            {
                throw new ArgumentException("NoSuchElementException");
            }
            else
            {
                T item = _items[head % _capacity];
                head++; Count--;
                return item;
            }
        }
        public T Peek()
        {
            if (Count == 0)
            {
                throw new ArgumentException("NoSuchElementException");
            }
            else
            {
                return _items[head % _capacity];
            }
        }
        public bool Contains(T item)
        {
            return _items.Contains(item);
        }
        private void ExpandedCapacityQueue()
        {
            T[] tempitems = _items;
            _items = new T[_capacity * 2];
            for (int i = 0; i < Count; i++)
            {
                _items[i] = tempitems[(head + i) % _capacity];
            }
            head = 0;
            _capacity = _capacity * 2;
        }
        #endregion
    }
}