尝试在C++中打印树(不使用x)

#include <iostream>

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

// 打印树的辅助函数
void printTree(TreeNode* root, int level) {
    if (root == nullptr) {
        return;
    }
    
    // 打印右子树
    printTree(root->right, level + 1);
    
    // 打印当前节点
    for (int i = 0; i < level; i++) {
        std::cout << "    ";
    }
    std::cout << root->val << std::endl;
    
    // 打印左子树
    printTree(root->left, level + 1);
}

// 打印树的入口函数
void printTree(TreeNode* root) {
    printTree(root, 0);
}

int main() {
    // 构造一个示例树
    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);
    
    // 打印树
    printTree(root);
    
    // 释放内存
    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;
}