yarrg/rssearch.c

   1 /**/
   2
   3 #include "rscommon.h"
   4
   5 DEBUG_DEFINE_DEBUGF(search);
   6 DEBUG_DEFINE_SOME_DEBUGF(filter,fildebugf);
   7
   8 typedef struct Neighbour {
   9   struct Neighbour *next;
  10   int islandid;
  11   int dist;
  12 } Neighbour;
  13
  14 static Neighbour **neighbours; /* neighbours[islandid]->islandid etc. */
  15 static sqlite3_stmt *ss_neigh;
  16
  17 static int ports[MAX_ROUTELEN];
  18 static int final_isle;
  19
  20 static Neighbour *get_neighbours(int isle) {
  21   Neighbour **np= &neighbours[isle];
  22   Neighbour *head= *np;
  23   if (head) return head;
  24
  25   SQL_BIND(ss_neigh, 1, isle);
  26   while (SQL_STEP(ss_neigh)) {
  27     Neighbour *add;
  28     NEW(add);
  29     add->islandid= sqlite3_column_int(ss_neigh, 0);
  30     add->dist= sqlite3_column_int(ss_neigh, 1);
  31     add->next= head;
  32     head= add;
  33   }
  34   SQL_MUST( sqlite3_reset(ss_neigh) );
  35
  36   *np= head;
  37   return head;
  38 }
  39
  40
  41 static PotentialResult ***strat_base;
  42
  43
  44 static double process_route(int nports, int totaldist,
  45                             double overestimate_excepting_tail) {
  46   int i;
  47   int leagues_divisor= totaldist + nports;
  48
  49   ctr_routes_considered++;
  50
  51   int wrong_final= final_isle && ports[nports-1] != final_isle;
  52
  53   debugf("========== ROUTE");
  54   for (i=0; i<nports; i++)
  55     debugf(" %d",ports[i]);
  56   debugf("\n");
  57
  58   double guess_absolute=0, guess_perleague=0;
  59   if (nports>=2) {
  60     int pair[2], i;
  61     pair[1]= ports[nports-1];
  62     guess_absolute= overestimate_excepting_tail;
  63
  64     for (i=0; i<nports; i++) {
  65       pair[0]= ports[i];
  66       IslandPair *ip= ipair_get_maybe(pair[0], pair[1]);
  67       if (!ip) continue;
  68       if (ip->route_tail_value < 0) {
  69         ctr_subroute_tails_valued++;
  70         ip->route_tail_value= value_route(2, pair, pair[0]!=pair[1]);
  71       }
  72       guess_absolute += ip->route_tail_value;
  73     }
  74     guess_perleague= guess_absolute / leagues_divisor;
  75
  76     if (wrong_final) {
  77       ctr_routes_wrongfinalelim++;
  78       debugf(" WFELIM\n");
  79       return guess_absolute;
  80     }
  81
  82     if (guess_absolute <= highscores_absolute[0].value &&
  83         guess_perleague <= highscores_perleague[0].value) {
  84       ctr_routes_quickelim++;
  85       debugf(" QELIM %f %f\n", guess_absolute, guess_perleague);
  86       return guess_absolute;
  87     }
  88   }
  89
  90   int finisle= ports[nports-1]; int finarch= isle2arch(finisle);
  91   int midarch= route2midarch(ports,nports);
  92
  93   PotentialResult **strat_fin= ONDEMAND(strat_base[finarch], narches);
  94   PotentialResult *strat= ONDEMAND(strat_fin[midarch], 1);
  95
  96   if (nports>=2) {
  97     if (guess_absolute <= strat->absolute &&
  98         guess_perleague <= strat->perleague) {
  99       ctr_routes_stratelim++;
 100       debugf(" ELIM %f %f\n", guess_absolute, guess_perleague);
 101       return guess_absolute;
 102     }
 103     debugf(" COMPUTE %f %f\n", guess_absolute, guess_perleague);
 104   }
 105
 106   ctr_routes_valued++;
 107
 108   double absolute= value_route(nports, ports, 0);
 109   double perleague= absolute / leagues_divisor;
 110
 111   if (wrong_final) {
 112     ctr_routes_wrongfinal++;
 113     return absolute;
 114   }
 115
 116   if (absolute <= strat->absolute &&
 117       perleague <= strat->perleague)
 118     return absolute;
 119
 120   debugf(" SOMEHOW BEST\n");
 121
 122   fildebugf("final %d:%3d mid %d ",finarch,finisle,midarch);
 123
 124 #define CHK(absperl)                                                          \
 125   fildebugf(#absperl " %15f", absperl);                                       \
 126   if (absperl < strat->absperl) {                                             \
 127     debugf("      ");                                                         \
 128   } else {                                                                    \
 129     int pos;                                                                  \
 130     ctr_newbests_strat_##absperl++;                                           \
 131     strat->absperl= absperl;                                                  \
 132     memcpy(strat->absperl##_ports, ports, sizeof(*ports) * nports);           \
 133     if (nports < MAX_ROUTELEN-1) strat->absperl##_ports[nports]= -1;          \
 134     fildebugf("** ");                                                         \
 135     for (pos=0; pos < nhighscores_##absperl; pos++)                           \
 136       if (highscores_##absperl[pos].pr == strat) goto found_##absperl;        \
 137     /* not found */                                                           \
 138     pos= -1;                                                                  \
 139    found_##absperl:                                                           \
 140     for (;;) {                                                                \
 141       pos++;                                                                  \
 142       if (pos >= nhighscores_##absperl-1) break; /* new top */                \
 143       if (highscores_##absperl[pos].value >= absperl) break; /* found spot */ \
 144       if (pos>0)                                                              \
 145         highscores_##absperl[pos-1]= highscores_##absperl[pos];               \
 146     }                                                                         \
 147     pos--;                                                                    \
 148     if (pos>0) {                                                              \
 149       highscores_##absperl[pos].value= absperl;                               \
 150       highscores_##absperl[pos].pr= strat;                                    \
 151     }                                                                         \
 152     fildebugf("@%2d", pos);                                                   \
 153   }
 154
 155   CHK(absolute)
 156   CHK(perleague)
 157
 158   fildebugf(" route");
 159
 160   for (i=0; i<nports; i++)
 161     fildebugf(" %d",ports[i]);
 162   fildebugf("\n");
 163
 164   return absolute;
 165 }
 166
 167 static void recurse(int last_isle,
 168                     int nports, /* excluding last_isle */
 169                     int totaldist /* including last_isle */,
 170                     double last_estimate) {
 171   ports[nports++]= last_isle;
 172   double estimate= process_route(nports, totaldist, last_estimate);
 173   if (nports >= MAX_ROUTELEN) return;
 174
 175   Neighbour *add;
 176   for (add= get_neighbours(last_isle); add; add=add->next) {
 177     int newdist= totaldist + add->dist;
 178     if (newdist > max_dist) continue;
 179
 180     recurse(add->islandid, nports, newdist, estimate);
 181   }
 182 }
 183
 184 void search(int start_isle, int final_isle_spec,
 185             PotentialResult ****strat_base_io) {
 186   strat_base= ONDEMAND(*strat_base_io, narches);
 187   final_isle= final_isle_spec <= 0 ? 0 : final_isle_spec;
 188   recurse(start_isle,0,0,1e6);
 189 }
 190
 191 int nhighscores_absolute, nhighscores_perleague;
 192 HighScoreEntry *highscores_absolute;
 193 HighScoreEntry *highscores_perleague;
 194
 195 int narches;
 196 char **archnames;
 197 int *islandid2arch;
 198
 199 void setup_search(void) {
 200   MCALLOC(neighbours, islandtablesz);
 201
 202   SQL_PREPARE(ss_neigh,
 203               "SELECT biid, dist FROM routes WHERE aiid=?");
 204
 205   int max_narches=
 206     sql_single_int(" SELECT count(*) FROM (\n"
 207                    "  SELECT DISTINCT archipelago\n"
 208                    "   FROM islands\n"
 209                    "  )");
 210   MCALLOC(archnames, max_narches);
 211   MCALLOC_INITEACH(islandid2arch, islandtablesz, *this=-1);
 212
 213   sqlite3_stmt *archs;
 214   SQL_PREPARE(archs,
 215               " SELECT islandid, archipelago\n"
 216               "  FROM islands\n"
 217               "  ORDER BY archipelago");
 218   while (SQL_STEP(archs)) {
 219     int isle= sqlite3_column_int(archs,0);
 220     const char *archname= (const char*)sqlite3_column_text(archs,1);
 221     int arch;
 222     for (arch=0; arch<narches; arch++)
 223       if (!strcmp(archnames[arch], archname)) goto found;
 224     assert(narches < max_narches);
 225     arch= narches++;
 226     archnames[arch]= masprintf("%s",archname);
 227   found:
 228     islandid2arch[isle]= arch;
 229   }
 230   sqlite3_finalize(archs);
 231 }