X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~yarrgweb/git?a=blobdiff_plain;f=yarrg%2Frssearch.c;h=d5a97a488604fb74db3f5c6ceaa7c686ef2613ed;hb=88a4cb4aba6429c13a848dafe3f82652cfc168cb;hp=f14b0cd7a87670e6785d6a34bcc2d0adca4e3a22;hpb=b5f936bf08ab82b34f9529b72946c0cd66ef5a62;p=ypp-sc-tools.web-live.git

diff --git a/yarrg/rssearch.c b/yarrg/rssearch.c
index f14b0cd..d5a97a4 100644
--- a/yarrg/rssearch.c
+++ b/yarrg/rssearch.c
@@ -36,18 +36,45 @@ static Neighbour *get_neighbours(int isle) {
 
 static double best_absolute, best_perleague;
 
-static void process_route(int nports, int totaldist) {
+static double process_route(int nports, int totaldist,
+			    double overestimate_excepting_tail) {
   int i;
+  int leagues_divisor= totaldist + nports;
 
   debugf("========== ROUTE");
   for (i=0; i<nports; i++)
     debugf(" %d",ports[i]);
   debugf("\n");
 
-  double absolute= value_route(nports, ports);
-  double perleague= absolute / (totaldist + nports);
+  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)
+	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) {
+      debugf(" ELIM %f %f\n", guess_absolute, guess_perleague);
+      return guess_absolute;
+    }
+    debugf(" COMPUTE %f %f\n", guess_absolute, guess_perleague);
+  }
+
+  double absolute= value_route(nports, ports, 0);
+  double perleague= absolute / leagues_divisor;
 
-  if (absolute < best_absolute && perleague < best_perleague) return;
+  if (absolute <= best_absolute && perleague <= best_perleague)
+    return absolute;
+
+  debugf(" SOMEHOW BEST\n");
 
 #define CHK(absperl) 					\
   fprintf(stderr,#absperl " %15f", absperl);		\
@@ -62,13 +89,16 @@ static void process_route(int nports, int totaldist) {
   for (i=0; i<nports; i++)
     fprintf(stderr," %d",ports[i]);
   putc('\n',stderr);
+
+  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, totaldist);
+  double estimate= process_route(nports, totaldist, last_estimate);
   if (nports >= MAX_ROUTELEN) return;
 
   Neighbour *add;
@@ -76,12 +106,12 @@ 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) {