Add heuritic to bitsets

2 files changed, 16 insertions, 0 deletions

diff --git a/set_bitsets.c b/set_bitsets.c
index 30e4dc9..53af83a 100644
--- a/set_bitsets.c
+++ b/set_bitsets.c
@@ -129,6 +129,21 @@ int elt_of_set(const set s){
 	assert(false);
 }
 
+int elt_of_set_heur(const set s, int h){
+    int N=nbCells(s.N), i;
+
+    if(s.tab[h/SCOD]>>(h%SCOD+1) !=0)
+	return h + dyadic_val(s.tab[h/SCOD]>>(h%SCOD+1)) + 1;
+
+    for(i=0; i<N; i++)
+	if(s.tab[(i+h/SCOD+1)%N] != 0)
+	    return i*SCOD+dyadic_val(s.tab[(i+h/SCOD+1)%N]);
+
+	printf("No element in an empty set!\n");
+	dump_set(s);
+	assert(false);
+}
+
 void set_add_ip(int x, set s){
     	unsigned long long ux = x;
     	if(! set_mem(ux, s)){
diff --git a/sets.h b/sets.h
index ebbed20..cbb37b8 100644
--- a/sets.h
+++ b/sets.h
@@ -60,6 +60,7 @@ bool set_mem(int x, const set s);
 bool sets_equal(const set a, const set b);
 
 int elt_of_set(const set s);
+int elt_of_set_heur(const set s, int h);
 
 set set_add(int x, const set s);
 void set_add_ip(int x, set s);