diff --git a/a3/binary_search_tree.c b/a3/binary_search_tree.c
index 0114dce..536dc91 100644
--- a/a3/binary_search_tree.c
+++ b/a3/binary_search_tree.c
@@ -2,6 +2,9 @@
 #include <stdlib.h>
 #include <string.h>
 
+int count_nodes(node_t *tree);
+void in_order_traversal(node_t *tree, int **ptr);
+
 node_t *build_tree(int *tree_data, size_t tree_data_len) {
     if (tree_data_len == 0) {
         return NULL;
@@ -56,3 +59,22 @@ int *sorted_data(node_t *tree) {
     in_order_traversal(tree, &ptr);
     return data;
 }
+
+int count_nodes(node_t *tree) {
+    if (tree == NULL) {
+        return 0;
+    }
+
+    return 1 + count_nodes(tree->left) + count_nodes(tree->right);
+}
+
+void in_order_traversal(node_t *tree, int **ptr) {
+    if (tree == NULL) {
+        return;
+    }
+
+    in_order_traversal(tree->left, ptr);
+    **ptr = tree->data;
+    (*ptr)++;
+    in_order_traversal(tree->right, ptr);
+}
\ No newline at end of file