bitset_t ProofUtil::InitialProofForOpponent(const HexBoard& brd,
HexColor toPlay)
{
// Add opponent played stones and deduction set.
const InferiorCells& inf = brd.GetInferiorCells();
bitset_t proof = brd.GetPosition().GetPlayed(!toPlay);
proof |= inf.DeductionSet(!toPlay);
// Add all semi-connections from the mustplay.
const VCList& lst = brd.Cons(!toPlay).GetList(VC::SEMI,
HexPointUtil::colorEdge1(!toPlay),
HexPointUtil::colorEdge2(!toPlay));
const bool useGreedy = brd.Builder().Parameters().use_greedy_union;
proof |= useGreedy ? lst.getGreedyUnion() : lst.getUnion();
// Add reversable reversers.
// The carriers do NOT need to be included in the proof, since
// they are captured by the (losing) player, not his opponent (for
// whom we are building the proof set).
// TODO: Currently, we just add the first reverser: we should see
// if any reverser is already in the proof, since then we wouldn't
// need to add one.
for (BitsetIterator p(inf.Reversible()); p; ++p)
{
const std::set<HexPoint>& reversers = inf.Reversers(*p);
proof.set(*reversers.begin());
}
// Add vulnerable killers and their carriers.
// TODO: Currently, we just add the first killer: we should see if
// any killer is already in the proof, since then we wouldn't need
// to add one.
for (BitsetIterator p(inf.Vulnerable()); p; ++p)
{
const std::set<VulnerableKiller>& killers = inf.Killers(*p);
proof.set((*killers.begin()).killer());
proof |= ((*killers.begin()).carrier());
}
return proof;
}
