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