private static IEnumerable <SearchState> CreateSearches(ICubieCube baseCube, DataSource dataSource)
{
for (byte rot = 0; rot <= 2; rot++)
{
foreach (var inv in new[] { false, true })
{
MutableCubieCube cb;
if (rot == 0)
{
// no rotation
cb = baseCube.Clone();
}
else if (rot == 1)
{
// conjugation by 120° rotation
cb = Symmetries.Basic.Cubes[32].Clone();
cb.Multiply(baseCube);
cb.Multiply(Symmetries.Basic.Cubes[16]);
}
else if (rot == 2)
{
// conjugation by 240° rotation
cb = Symmetries.Basic.Cubes[16].Clone();
cb.Multiply(baseCube);
cb.Multiply(Symmetries.Basic.Cubes[32]);
}
else
{
throw new ArgumentException("Rotation should be 1,2, or 3");
}
if (inv)
{
cb = cb.Invert(); // invert cube
}
var coCube = cb.ToCoordinateCube(dataSource);
var search = new SearchState(inv, rot, coCube, ImmutableLinkedList <Move> .Empty, false);
yield return(search);
}
}
}
public void MaybeAddSearch(SearchState searchState)
{
if (_seenCubes.TryAdd(searchState.Cube, searchState.MovesSoFar.Count))
{
DepthCubes.Add(searchState);
return;
}
while (true)
{
if (!_seenCubes.TryGetValue(searchState.Cube, out var previousMoves) ||
previousMoves <= searchState.MovesSoFar.Count)
{
return; //Previous solution is as good as or better
}
if (!_seenCubes.TryUpdate(searchState.Cube, searchState.MovesSoFar.Count, previousMoves))
{
continue; //Failure updating - try again
}
DepthCubes.Add(searchState);
return;
}
}