port compress_subtree_to_parent_node from Rust to C

This recursive function performs parallel parent node hashing, which is
an important optimization.

1 files changed, 1 insertions, 0 deletions

diff --git a/c/main.c b/c/main.c
index 8638303..9ef7bce 100644
--- a/c/main.c
+++ b/c/main.c
@@ -157,5 +157,6 @@ int main(int argc, char **argv) {
     free(out);
     feature = (feature - mask) & mask;
   } while (feature != 0);
+  free(buf);
   return 0;
 }