Efficient data structure for Zobrist keys
<p>Zobrist keys are 64bit hashed values used in board games to univocally represent different positions found during a tree search. They are usually stored in arrays having a size of 1000K entries or more (each entry is about 10 bytes long). The table is usually accessed by <code>hashKey % size</code> as index. What kind of STL container would you use to represent this sort of table? Consider that since the size of the table is limited collisions might happen. With a "plain" array I would have to handle this case, so I thought of an unordered_map, but since the implementation is not specified, I am not sure how efficient it will be while the map is being populated. </p>
