C++返回指针指针|二叉树get节点逐级获取

#include <iostream>

// 定义二叉树节点结构
struct TreeNode {
    int val;
    TreeNode* left;
    TreeNode* right;
    TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
};

// 逐级获取二叉树节点的值
void getTreeNodeValue(TreeNode** root) {
    if (*root != nullptr) {
        std::cout << "Node value: " << (*root)->val << std::endl;
        getTreeNodeValue(&((*root)->left));
        getTreeNodeValue(&((*root)->right));
    }
}

int main() {
    // 构建二叉树
    TreeNode* root = new TreeNode(1);
    root->left = new TreeNode(2);
    root->right = new TreeNode(3);
    root->left->left = new TreeNode(4);
    root->left->right = new TreeNode(5);
    
    // 逐级获取节点值
    getTreeNodeValue(&root);
    
    // 释放内存
    delete root->left->left;
    delete root->left->right;
    delete root->left;
    delete root->right;
    delete root;
    
    return 0;
}