Source of DoubleHashingHashTable.java

  1: //DoubleHashingHashTable.java (from zyDE 5.10.1)

  3: public class DoubleHashingHashTable extends OpenAddressingHashTable
  4: {
  5:     public DoubleHashingHashTable(int initialCapacity)
  6:     {
  7:         super(initialCapacity);
  8:     }

 10:     public DoubleHashingHashTable()
 11:     {
 12:         // Initialize with an initial capacity of 11
 13:         this(11);
 14:     }

 16:     // The secondary hash function. Many different functions can
 17:     // be used here. The function used here is a common one, with
 18:     // different (usually prime number) constants used where the 7 is.
 19:     private int h2(Object key)
 20:     {
 21:         return 7 - hash(key) % 7;
 22:     }

 24:     // Returns the bucket index for the specified key and i value using the
 25:     // double hashing probing sequence.
 26:     @Override
 27:     protected int probe(Object key, int i)
 28:     {
 29:         return (hash(key) + i * h2(key)) % table.length;
 30:     }
 31: }