diff --git a/a3/binary_search_tree.c b/a3/binary_search_tree.c
new file mode 100644
index 0000000..4c65468
--- /dev/null
+++ b/a3/binary_search_tree.c
@@ -0,0 +1,67 @@
+#include "binary_search_tree.h"
+#include <stdlib.h>
+
+
+node_t *new_node(int data) {
+    node_t *node = malloc(sizeof(node_t));
+    if (node) {
+        node->data = data;
+        node->left = NULL;
+        node->right = NULL;
+    }
+    return node;
+}
+
+
+node_t *insert(node_t *root, int data) {
+    if (root == NULL) {
+        return new_node(data);
+    }
+    if (data <= root->data) {
+        root->left = insert(root->left, data);
+    } else {
+        root->right = insert(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(root, tree_data[i]);
+    }
+    return root;
+}
+
+
+void free_nodes(node_t *node) {
+    if (node != NULL) {
+        free_nodes(node->left);
+        free_nodes(node->right);
+        free(node);
+    }
+}
+
+
+void free_tree(node_t *tree) {
+    free_nodes(tree);
+}
+
+
+void inorder_traversal(node_t *node, int *array, int *index) {
+    if (node != NULL) {
+        inorder_traversal(node->left, array, index);
+        array[(*index)++] = node->data;
+        inorder_traversal(node->right, array, index);
+    }
+}
+
+
+int *sorted_data(node_t *tree) {
+    int *array = malloc(sizeof(int) * 100); 
+    int index = 0;
+    inorder_traversal(tree, array, &index);
+    return array;
+}
+