Update 'a3/binary_search_tree.c'

a3/binary_search_tree.c

@@ -0,0 +1,89 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+typedef struct node {
+    struct node *right;
+    struct node *left;
+    int data;
+} node_t;
+
+
+node_t *insert_node(node_t *root, int data);
+void free_tree(node_t *tree);
+int *sorted_data(node_t *tree, int *count);
+void inorder_traversal(node_t *tree, int *arr, int *index);
+
+
+node_t *insert_node(node_t *root, int data) {
+    if (root == NULL) {
+        node_t *new_node = malloc(sizeof(node_t));
+        if (new_node == NULL) {
+            return NULL; 
+        }
+        new_node->data = data;
+        new_node->left = new_node->right = NULL;
+        return new_node;
+    }
+    if (data <= root->data) {
+        root->left = insert_node(root->left, data);
+    } else {
+        root->right = insert_node(root->right, data);
+    }
+    return root;
+}
+
+
+void free_tree(node_t *tree) {
+    if (tree != NULL) {
+        free_tree(tree->left);
+        free_tree(tree->right);
+        free(tree);
+    }
+}
+
+
+void inorder_traversal(node_t *tree, int *arr, int *index) {
+    if (tree != NULL) {
+        inorder_traversal(tree->left, arr, index);
+        arr[*index] = tree->data;
+        (*index)++;
+        inorder_traversal(tree->right, arr, index);
+    }
+}
+
+
+int *sorted_data(node_t *tree, int *count) {
+    *count = 0;
+    inorder_traversal(tree, NULL, count);
+
+    int *arr = malloc(sizeof(int) * (*count));
+    if (arr == NULL) {
+        return NULL;
+    }
+    int index = 0;
+    inorder_traversal(tree, arr, &index);
+    return arr;
+}
+
+int main() {
+    node_t *root = NULL;
+    int tree_data[] = {4, 2, 6, 1, 3, 5, 7};
+    int tree_data_len = sizeof(tree_data) / sizeof(tree_data[0]);
+
+    for (int i = 0; i < tree_data_len; i++) {
+        root = insert_node(root, tree_data[i]);
+    }
+
+    int count = 0;
+    int *sorted = sorted_data(root, &count);
+    
+    printf("Sorted data: ");
+    for (int i = 0; i < count; i++) {
+        printf("%d ", sorted[i]);
+    }
+    printf("\n");
+
+    free(sorted);
+    free_tree(root);
+    return 0;
+}