DataStructure/DataStructure/hashTableStructure/HashTable/SimpleHashTable.cs

namespace hashTableStructure.HashTable
{
    class SimpleHashTable
    {
        private const int INITIAL_SIZE = 16;
        private int _size;
        private Node[] _buckets;

        public SimpleHashTable()
        {
            _size = INITIAL_SIZE;
            _buckets = new Node[_size];
        }

        public void Put(object key, object value)
        {
            int index = HashFunction(key);
            if (_buckets[index] == null)
            {
                _buckets[index] = new Node(key, value);
            }
            else
            {
                Node newNode = new Node(key, value);
                newNode.Next = _buckets[index];
                _buckets[index] = newNode;
            }
        }

        public object Get(object key)
        {
            int index = HashFunction(key);
            if (_buckets[index] != null)
            {
                for (Node n = _buckets[index]; n != null; n = n.Next)
                {
                    if (n.Key == key)
                        return n.Value;
                }
            }

            return null;
        }

        public bool Contains(object key)
        {
            int index = HashFunction(key);
            if (_buckets[index] != null)
            {
                for (Node n = _buckets[index]; n != null; n = n.Next)
                {
                    if (n.Key == key)
                        return true;
                }
            }

            return false;
        }

        protected virtual int HashFunction(object key)
        {
            return Math.Abs(key.GetHashCode() + 1 + ((key.GetHashCode() >> 5) + 1) % _size) % _size;
        }
    }
}