在非STL二叉树中打印出具有两个子项的父项时出现问题

#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) {}
};

// 辅助函数：递归遍历二叉树并打印具有两个子项的父项
void printParentsWithTwoChildren(TreeNode* root) {
    if (root == nullptr) return;

    // 检查当前节点是否具有两个子项
    if (root->left != nullptr && root->right != nullptr) {
        std::cout << "Parent with two children: " << root->val << std::endl;
    }

    // 递归遍历左子树和右子树
    printParentsWithTwoChildren(root->left);
    printParentsWithTwoChildren(root->right);
}

int main() {
    // 构建一个示例二叉树
    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);
    root->right->left = new TreeNode(6);
    root->right->right = new TreeNode(7);

    // 打印具有两个子项的父项
    printParentsWithTwoChildren(root);

    // 释放内存（简单示例，实际应用中应使用智能指针或手动释放）
    delete root->left->left;
    delete root->left->right;
    delete root->right->left;
    delete root->right->right;
    delete root->left;
    delete root->right;
    delete root;

    return 0;
}