Merge remote-tracking branch 'sgt/master'

[matchsticks-search.git] / main.c

diff --git a/main.c b/main.c
index 69023658988f0526de782d0ea25a51b54e092a10..2fc3a51f86979e5468fb4237cdd4efb760e4d089 100644 (file)
--- a/main.c
+++ b/main.c
@@ -94,6 +94,9 @@ static double best;
 static glp_prob *best_prob;
 static AdjWord *best_adjmatrix;
 
+static int n_over_best;
+static int *weight;
+
 static unsigned printcounter;
 
 static void iterate(void);
@@ -107,6 +110,11 @@ static void progress_eol(void) {
   fflush(stderr);
 }
 
+static void set_best(double new_best) {
+  best = new_best;
+  n_over_best = n / best;
+}
+
 /*----- multicore support -----*/
 
 /*
@@ -309,7 +317,7 @@ static void multicore_check_for_new_best(void) {
     if (!got) break;
     assert(got == sizeof(msg));
     if (msg > best)
-      best = msg;
+      set_best(msg);
     mc_bus_read += sizeof(msg);
   }
 }
@@ -333,6 +341,8 @@ static void prep(void) {
   adjmatrix = xalloc_adjmatrix();
   glp_term_out(GLP_OFF);
   setlinebuf(stderr);
+  weight = calloc(sizeof(*weight), m);  assert(weight);
+  n_over_best = INT_MAX;
 }
 
 static AdjWord one_adj_bit(int bitnum) {
@@ -555,7 +565,7 @@ static void optimise(bool doprint) {
 
   HAVE_PRINTED;
 
-  best = got;
+  set_best(got);
   multicore_found_new_best();
 
   if (best_prob) glp_delete_prob(best_prob);
@@ -594,8 +604,20 @@ static void iterate_recurse(int i, AdjWord min) {
     if (i == 0 && (adjmatrix[i] & (1+adjmatrix[i])))
       goto again;
 
+    for (int j = 0; j < m; j++)
+      if (adjmatrix[i] & one_adj_bit(j))
+        weight[j]++;
+    for (int j = 0; j < m; j++)
+      if (weight[j] >= n_over_best)
+        goto takeout;
+
     iterate_recurse(i+1, adjmatrix[i]);
 
+  takeout:
+    for (int j = 0; j < m; j++)
+      if (adjmatrix[i] & one_adj_bit(j))
+        weight[j]--;
+
   again:
     if (adjmatrix[i] == adjall)
       return;