diff --git a/a3/binary_search_tree.c b/a3/binary_search_tree.c
index e69de29..4294728 100644
--- a/a3/binary_search_tree.c
+++ b/a3/binary_search_tree.c
@@ -0,0 +1,63 @@
+#include "binary_search_tree.h"
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+static node_t *create_node(int data) {
+    node_t *new_node = malloc(sizeof(node_t));
+    if (new_node != NULL) {
+        new_node->data = data;
+        new_node->left = NULL;
+        new_node->right = NULL;
+    }
+    return new_node;
+}
+
+static node_t *insert_node(node_t *root, int data) {
+    if (root == NULL) {
+        return create_node(data);
+    }
+    if (data <= root->data) {
+        root->left = insert_node(root->left, data);
+    } else {
+        root->right = insert_node(root->right, data);
+    }
+    return root;
+}
+
+
+node_t *build_tree(int *tree_data, size_t tree_data_len) {
+    node_t *root = NULL;
+    for (size_t i = 0; i < tree_data_len; i++) {
+        root = insert_node(root, tree_data[i]);
+    }
+    return root;
+}
+
+
+void free_tree(node_t *tree) {
+    if (tree != NULL) {
+        free_tree(tree->left);
+        free_tree(tree->right);
+        free(tree);
+    }
+}
+
+
+static void inorder_traversal(node_t *root, int *sorted_array, size_t *index) {
+    if (root != NULL) {
+        inorder_traversal(root->left, sorted_array, index);
+        sorted_array[(*index)++] = root->data;
+        inorder_traversal(root->right, sorted_array, index);
+    }
+}
+
+int *sorted_data(node_t *tree) {
+    size_t index = 0;
+    int *sorted_array = malloc(sizeof(int) * count_nodes(tree));
+    if (sorted_array == NULL) {
+        return NULL; 
+    }
+    inorder_traversal(tree, sorted_array, &index);
+    return sorted_array;
+}