Faster optimal solver.

This is a pretty big one, but unfortunately performance only improved by about 5%.
I implemented one of the main ideas of nxopt, that is switching to the
inverse scramble on the fly if it gives a lower branching factor.
On the one hand it makes sense that it does not have such a huge impact, since
it only rarely happens that we do have a lower branching factor on inverse, but
on the other hand I am quite sad that the improvement is barely noticeable :-(
Maybe the problem is that I have introduced a lot of new overhead and I can improve
that in the future. Or maybe I am just overlooking something stupid.

1 files changed, 12 insertions, 2 deletions

diff --git a/src/utils.c b/src/utils.c
index 1c829c4..e0d3268 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -272,7 +272,17 @@ swap(int *a, int *b)
         int aux;
 
         aux = *a;
-        *a = *b;
-        *b = aux;
+        *a  = *b;
+        *b  = aux;
+}
+
+void
+swapu64(uint64_t *a, uint64_t *b)
+{
+        uint64_t aux;
+
+        aux = *a;
+        *a  = *b;
+        *b  = aux;
 }