diff --git a/a3/binary_search_tree.c b/a3/binary_search_tree.c
index c1463eb..4b52055 100644
--- a/a3/binary_search_tree.c
+++ b/a3/binary_search_tree.c
@@ -9,23 +9,25 @@ typedef struct Node {
 Node* newNode(int data);
 Node* insert(Node* node, int data);
 int search(Node* root, int x);
+void build_tree(); // Deklarace funkce build_tree
+void free_tree(); // Deklarace funkce free_tree
 
 Node* newNode(int data) {
     Node* node = (Node*)malloc(sizeof(Node));
     node->data = data;
     node->left = NULL;
     node->right = NULL;
-    return(node);
+    return node;
 }
 
 Node* insert(Node* node, int data) {
     if (node == NULL) {
-        return(newNode(data));
+        return newNode(data);
     }
     else {
         if (data <= node->data) node->left = insert(node->left, data);
         else node->right = insert(node->right, data);
-        return(node);
+        return node;
     }
 }
 
@@ -35,3 +37,13 @@ int search(Node* root, int x) {
     else if(root->data < x) return search(root->right, x);
     else return search(root->left, x);
 }
+
+// Implementace funkce build_tree
+void build_tree() {
+    // Zde implementujte vytvoření stromu
+}
+
+// Implementace funkce free_tree
+void free_tree() {
+    // Zde implementujte uvolnění paměti použité pro strom
+}