add parethesis support

1 files changed, 7 insertions, 0 deletions

diff --git a/tree.c b/tree.c
index b53ece2..fbb561a 100644
--- a/tree.c
+++ b/tree.c
@@ -62,3 +62,10 @@ void fprintTree(FILE *stream, node *root, int level) {
 void printTree(node *root, int level) {
   fprintTree(stdout, root, level);
 }
+
+void free_node(node *n) {
+  if (n->lhs) free_node(n->lhs);
+  if (n->rhs) free_node(n->rhs);
+  free(n);
+}
+