我用C++编写了一个方法来打印树型类的前序，但它显示分割错误

#include <iostream>

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

// 前序遍历打印树
void printPreorder(TreeNode* root) {
    if (root == nullptr) {
        return;
    }

    // 打印当前节点的值
    std::cout << root->val << " ";

    // 递归遍历左子树
    printPreorder(root->left);

    // 递归遍历右子树
    printPreorder(root->right);
}

int main() {
    // 构建一个示例树
    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);

    // 打印树的前序遍历结果
    printPreorder(root);

    // 释放内存
    delete root->left->left;
    delete root->left->right;
    delete root->left;
    delete root->right;
    delete root;

    return 0;
}