C언어 이진탐색트리 구현

#include <stdio.h>
#include <stdlib.h>

struct node {
    int data;
    struct node *left;
    struct node *right;
} Node;

// 데이터 삽입(recursion)
void insert(struct node **root, int data) {
    struct node* ptr;
    struct node* newNode = (struct node*)malloc(sizeof(struct node));
    newNode->data = data;
    newNode->left = newNode->right = NULL;

    if(*root == NULL){
        *root = newNode;
        return;
    }

    ptr = *root;

    while(ptr){
        if(data < ptr->data){
            if(ptr->left == NULL){
                ptr->left = newNode;
                return;
            }
            else{
                ptr = ptr->left;
            }
        }
        else{
            if(ptr->right == NULL){
                ptr->right = newNode;
                return;
            }
            else{
                ptr = ptr->right;
            }
        }
    }
}

// 전위(preorder)탐색(recursion)
void preOrder(struct node *root) {
    if(root == NULL) return;
    printf("%d ", root->data);
    preOrder(root->left);
    preOrder(root->right);
}

// 중위(inorder)탐색(recursion)
void inOrder(struct node *root) {
    if(root == NULL) return;
    inOrder(root->left);
    printf("%d ", root->data);
    inOrder(root->right);
}

// 후위(postorder)탐색(recursion)
void postOrder(struct node *root) {
    if(root == NULL) return;
    postOrder(root->left);
    postOrder(root->right);
    printf("%d ", root->data);
}

// 노드의 개수(recursion)
int size(struct node *root) {
    if(root == NULL) return 0;
    return 1 + size(root->left) + size(root->right);
}

// 높이(recursion)
int height(struct node *root) {
    if(root == NULL) return 0;
    if(root->left == NULL && root->right == NULL) return 0;

    int leftHeight = height(root->left);
    int rightHeight = height(root->right);
    return 1 + (leftHeight>= rightHeight ? leftHeight : rightHeight);
}

// 미러 이미지로 변환하기(recursion)
void mirror(struct node **root) {
    if(*root == NULL) return;
    mirror(&(*root)->left);
    mirror(&(*root)->right);
    struct node *tmp = (*root)->left;
    (*root)->left = (*root)->right;
    (*root)->right = tmp;
}

// 노드에 저장된 데이터의 값의 합 구하기(recursion)
int sumOfWeight(struct node *root) {
    if(root == NULL) return 0;
    return sumOfWeight(root->left) + sumOfWeight(root->right) + root->data;
}

// 루트노드부터 단말노드까지의 경로 상의 데이터의 최대합(recusrion)
int maxPathWeight(struct node *root) {
    if(root == NULL) return 0;
    int leftWeight, rightWeight;
    leftWeight = maxPathWeight(root->left);
    rightWeight = maxPathWeight(root->right);
    return root->data + (leftWeight>=rightWeight ? leftWeight : rightWeight);
}

// 트리노드의 동적 메모리 해제하기(recursion)
void destruct(struct node **root) {
    if(*root == NULL) return;
    destruct(&((*root)->left));
    destruct(&((*root)->right));
    free(*root);
    *root = NULL;
}