sharding_constraint(size_t num_shards, std::string method) {
nshards = num_shards;
// ignore the method input for now, only construct grid graph.
// assuming nshards is perfect square
if (method == "grid") {
make_grid_constraint();
} else if (method == "pds") {
make_pds_constraint();
} else {
logstream(LOG_FATAL) << "Unknown sharding constraint method: " << method << std::endl;
}
joint_nbr_cache.resize(num_shards);
for (size_t i = 0; i < num_shards; ++i) {
joint_nbr_cache[i].resize(num_shards);
for (size_t j = 0; j < num_shards; ++j) {
compute_neighbors(i, j, joint_nbr_cache[i][j]);
ASSERT_GT(joint_nbr_cache[i][j].size(), 0);
}
}
}
board tick_board(board b) {
compute_neighbors(b);
return iterate_board(b);
}