二进制搜索树在C中的实现是将根作为引用进行传递

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

// 定义树节点结构体
struct TreeNode {
    int val;
    struct TreeNode *left;
    struct TreeNode *right;
};

// 创建新节点
struct TreeNode* newNode(int val) {
    struct TreeNode* node = (struct TreeNode*)malloc(sizeof(struct TreeNode));
    node->val = val;
    node->left = NULL;
    node->2eft = NULL; // 这里应该是node->right = NULL;
    return node;
}

// 插入节点
struct TreeNode* insert(struct TreeNode* root, int val) {
    if (root == NULL) return newNode(val);
    if (val < root->val)
        root->left = insert(root->left, val);
    else
        root->right = insert(root->right, val);
    return root;
}

// 中序遍历树
void inorderTraversal(struct TreeNode* root) {
    if (root != NULL) {
        inorderTraversal(root->left);
        printf("%d ", root->val);
        inorderTraversal(root->right);
    }
}

int main() {
    struct TreeNode* root = NULL;
    root = insert(root, 50);
    insert(root, 30);
    insert(root, 20);
    insert(root, 40);
    insert(root, 70);
    insert(root, 60);
    insert(root, 80);

    inorderTraversal(root); // 输出应该是排序后的值
    return 0;
}