// Construction
internal TranspositionTable()
{
Table = new TranspositionEntry[TABLE_SIZE];
for (int i = 0; i < TABLE_SIZE; i++)
{
Table[i] = new TranspositionEntry();
}
}
// bool LookupBoard( jcBoard theBoard, jcMove theMove )
// Verify whether there is a stored evaluation for a given board.
// If so, return TRUE and copy the appropriate values into the
// output parameter
internal bool TryLookupBoard(Board _board, out TranspositionEntry _entry)
{
// Find the board's hash position in Table
int key = Math.Abs(_board.GetHashCode() % TABLE_SIZE);
TranspositionEntry entry = Table[key];
_entry = entry;
// If the entry is an empty placeholder, we don't have a match
if (entry.EvaluationType == EvaluationType.None)
{
return(false);
}
// Check for a hashing collision!
if (entry.CollisionKey != _board.HashCollisionsKey())
{
return(false);
}
// Now, we know that we have a match! Copy it into the output parameter
// and return
return(true);
}
