routesearch: use presolver

[ypp-sc-tools.db-live.git] / yarrg / rssearch.c

diff --git a/yarrg/rssearch.c b/yarrg/rssearch.c
index c51aae02f655571571b246aec89e578e2aef2b58..87914a8cd89232748821b717791ade6810e6196e 100644 (file)
--- a/yarrg/rssearch.c
+++ b/yarrg/rssearch.c
@@ -2,6 +2,8 @@
 
 #include "rscommon.h"
 
+DEBUG_DEFINE_DEBUGF(search);
+
 typedef struct Neighbour {
   struct Neighbour *next;
   int islandid;
@@ -32,26 +34,78 @@ static Neighbour *get_neighbours(int isle) {
   return head;
 }
 
-static double bestsofar;
-
-static void process_route(int nports) {
-  double value= value_route(nports, ports);
-  if (value < bestsofar) return;
+static double best_absolute, best_perleague;
 
-  fprintf(stderr,"value %20f route", value);
+static double process_route(int nports, int totaldist,
+                           double overestimate_excepting_tail) {
   int i;
+  int leagues_divisor= totaldist + nports;
+
+  ctr_routes_considered++;
+
+  debugf("========== ROUTE");
+  for (i=0; i<nports; i++)
+    debugf(" %d",ports[i]);
+  debugf("\n");
+
+  if (nports>=2) {
+    int pair[2], i;
+    pair[1]= ports[nports-1];
+    double guess_absolute= overestimate_excepting_tail;
+    
+    for (i=0; i<nports; i++) {
+      pair[0]= ports[i];
+      IslandPair *ip= ipair_get_maybe(pair[0], pair[1]);
+      if (!ip) continue;
+      if (ip->route_tail_value < 0) {
+       ctr_subroute_tails_valued++;
+       ip->route_tail_value= value_route(2, pair, pair[0]!=pair[1]);
+      }
+      guess_absolute += ip->route_tail_value;
+    }
+    double guess_perleague= guess_absolute / leagues_divisor;
+
+    if (guess_absolute <= best_absolute && guess_perleague <= best_perleague) {
+      ctr_routes_eliminated++;
+      debugf(" ELIM %f %f\n", guess_absolute, guess_perleague);
+      return guess_absolute;
+    }
+    debugf(" COMPUTE %f %f\n", guess_absolute, guess_perleague);
+  }
+
+  ctr_routes_valued++;
+
+  double absolute= value_route(nports, ports, 0);
+  double perleague= absolute / leagues_divisor;
+
+  if (absolute <= best_absolute && perleague <= best_perleague)
+    return absolute;
+
+  debugf(" SOMEHOW BEST\n");
+
+#define CHK(absperl)                                   \
+  fprintf(stderr,#absperl " %15f", absperl);           \
+  if (absperl < best_##absperl) fputs("   ",stderr);   \
+  else { best_##absperl= absperl; fputs("** ",stderr); }
+
+  CHK(absolute)
+  CHK(perleague)
+
+  fputs(" route",stderr);
+
   for (i=0; i<nports; i++)
     fprintf(stderr," %d",ports[i]);
   putc('\n',stderr);
-  
-  bestsofar= value;
+
+  return absolute;
 }
 
 static void recurse(int last_isle,
                    int nports, /* excluding last_isle */
-                   int totaldist /* including last_isle */) {
+                   int totaldist /* including last_isle */,
+                   double last_estimate) {
   ports[nports++]= last_isle;
-  process_route(nports);
+  double estimate= process_route(nports, totaldist, last_estimate);
   if (nports >= MAX_ROUTELEN) return;
 
   Neighbour *add;
@@ -59,12 +113,12 @@ static void recurse(int last_isle,
     int newdist= totaldist + add->dist;
     if (newdist > max_dist) continue;
 
-    recurse(add->islandid, nports, newdist);
+    recurse(add->islandid, nports, newdist, estimate);
   }
 }
 
 void search(int start_isle) {
-  recurse(start_isle,0,0);
+  recurse(start_isle,0,0,1e6);
 }
 
 void setup_search(void) {