// Constructs a hash table with specified capacity.
public HashTable(int initialCapacity)
{
if (initialCapacity < 1)
{
throw new ArgumentOutOfRangeException("initialCapacity");
}
_array = new HashTableArray <TKey, TValue>(initialCapacity);
// When the count exceeds this value, the next Add will cause the array to grow.
_maxItemsAtCurrentSize = (int)(initialCapacity * _fillFactor) + 1;
}
public void Add(TKey key, TValue value) // O(1) on average. O(n+1) when array growth occrus.
{
// Adds layer of abstraction over HashTableArray class.
// If we are at capacity, the array needs to grow.
if (_count >= _maxItemsAtCurrentSize)
{
// Allocate a larger array
HashTableArray <TKey, TValue> largerArray =
new HashTableArray <TKey, TValue>(_array.Capacity * 2);
// Re-add each item to the new array
foreach (HashTableNodePair <TKey, TValue> node in _array.Items)
{
largerArray.Add(node.Key, node.Value);
}
// The larger array is now the hash table storage.
_array = largerArray;
// Update the new max items cached value.
_maxItemsAtCurrentSize = (int)(_array.Capacity * _fillFactor + 1);
}
_array.Add(key, value);
_count++;
}
