“program”

a3/binary_search_tree.c

@@ -1,65 +1,64 @@
 #include "binary_search_tree.h"
 #include <stdlib.h>
 
+static node_t *insert_node(node_t *root, int value);
+static void inorder_traversal(node_t *node, int *array, int *index);
 
-node_t *new_node(int data) {
-    node_t *node = malloc(sizeof(node_t));
-    if (node) {
-        node->data = data;
-        node->left = NULL;
-        node->right = NULL;
+static node_t *new_node(int value) {
+    node_t *node = (node_t *)malloc(sizeof(node_t));
+    if (node == NULL) {
+        return NULL;
     }
+    node->data = value;
+    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]);
+        root = insert_node(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);
+static node_t *insert_node(node_t *root, int value) {
+    if (root == NULL) {
+        return new_node(value);
+    }
+    if (value < root->data) {
+        root->left = insert_node(root->left, value);
+    } else {
+        root->right = insert_node(root->right, value);
     }
+    return root;
 }
 
-
 void free_tree(node_t *tree) {
-    free_nodes(tree);
+    if (tree == NULL) {
+        return;
+    }
+    free_tree(tree->left);
+    free_tree(tree->right);
+    free(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);
+static void inorder_traversal(node_t *node, int *array, int *index) {
+    if (node == NULL) {
+        return;
     }
+    inorder_traversal(node->left, array, index);
+    array[*index] = node->data;
+    (*index)++;
+    inorder_traversal(node->right, array, index);
 }
 
-
 int *sorted_data(node_t *tree) {
-    int *array = malloc(sizeof(int) * 100); 
+    if (tree == NULL) {
+        return NULL;
+    }
+    int *array = (int *)malloc(sizeof(int) * 100);
     int index = 0;
     inorder_traversal(tree, array, &index);
     return array;