Function weight_alloc_nt0

library/src/heuristic_sorting/heuristic_sorting.cpp:335–479

Placeholder for the rest of the functions to be moved

// Placeholder for the rest of the functions to be moved
void weight_alloc_nt0(HeuristicContext& context) {
  int aggr = context.tpos.aggr[context.suit];

  /* Discourage a suit selection where the search tree appears larger
     than for the alternative suits: the search is estimated to be
     small when the added number of alternative cards to play for
     the opponents is small. */

  unsigned short suit_count_lh = context.tpos.length[lho[context.lead_hand]][context.suit];
  unsigned short suit_count_rh = context.tpos.length[rho[context.lead_hand]][context.suit];

  // Why?
  int countLH = (suit_count_lh == 0 ? context.curr_trick + 1 : suit_count_lh) << 2;
  int countRH = (suit_count_rh == 0 ? context.curr_trick + 1 : suit_count_rh) << 2;

  int suit_weight_d = - (((countLH + countRH) << 5) / 19);
  if (context.tpos.length[partner[context.lead_hand]][context.suit] == 0)
    suit_weight_d += -9;

  for (int k = context.last_num_moves; k < context.num_moves; k++)
  {
    int suit_weight_delta = suit_weight_d;
    int r_rank = rel_rank[aggr][context.mply[k].rank];

    if (context.tpos.winner[context.suit].rank == context.mply[k].rank ||
        (context.tpos.rank_in_suit[partner[context.lead_hand]][context.suit] >
         (context.tpos.rank_in_suit[lho[context.lead_hand]][context.suit] |
          context.tpos.rank_in_suit[rho[context.lead_hand]][context.suit])))
    {
      // Can win trick, ourselves or partner.
      // FIX: No distinction?
      /* Discourage suit if RHO has second best card.
         Exception: RHO has singleton. */
      if (context.tpos.second_best[context.suit].hand == rho[context.lead_hand])
      {
        if (suit_count_rh != 1)
          suit_weight_delta += -1;
      }
      /* Encourage playing suit if LHO has second highest rank. */
      else if (context.tpos.second_best[context.suit].hand == lho[context.lead_hand])
      {
        if (suit_count_lh != 1)
          suit_weight_delta += 22;
        else
          suit_weight_delta += 16;
      }

      /* Higher weight if also second best rank is present on
         current side to play, or if second best is a singleton
         at LHO or RHO. */

      if (((context.tpos.second_best[context.suit].hand != lho[context.lead_hand])
           || (suit_count_lh == 1)) &&
          ((context.tpos.second_best[context.suit].hand != rho[context.lead_hand])
           || (suit_count_rh == 1)))
        context.mply[k].weight = suit_weight_delta + 45 + r_rank;
      else
        context.mply[k].weight = suit_weight_delta + 18 + r_rank;