+#include <cstdio>
+
+#if 0
+#define ASSERT_NODE(orig, res) do { \
+ if (res < -1 || res >= par->n|| (res != -1 && res < orig)) \
+ fprintf(stderr, \
+ "Assertion failure: original node %i, result %i, line %i\n", \
+ orig, res, __LINE__); \
+ } while (0)
+#else
+#define ASSERT_NODE(orig, res)
+#endif
+