将二叉树的节点插入链表(C++)

#include <iostream>
#include <queue>

using namespace std;

// 二叉树节点的定义
struct TreeNode {
    int val;
    TreeNode* left;
    TreeNode* right;
    TreeNode(int x) : val(x), left(NULL), right(NULL) {}
};

// 链表节点的定义
struct ListNode {
    int val;
    ListNode* next;
    ListNode(int x) : val(x), next(NULL) {}
};

// 将二叉树的节点插入链表
ListNode* insertBinaryTreeToLinkedList(TreeNode* root) {
    if (root == NULL) {
        return NULL;
    }

    // 使用队列进行层次遍历
    queue<TreeNode*> q;
    q.push(root);

    ListNode* dummy = new ListNode(0);
    ListNode* curr = dummy;

    while (!q.empty()) {
        TreeNode* node = q.front();
        q.pop();

        // 创建新的链表节点
        ListNode* newNode = new ListNode(node->val);
        curr->next = newNode;
        curr = curr->next;

        // 将左右子节点加入队列
        if (node->left) {
            q.push(node->left);
        }
        if (node->right) {
            q.push(node->right);
        }
    }

    return dummy->next;
}

// 打印链表
void printLinkedList(ListNode* head) {
    ListNode* curr = head;
    while (curr != NULL) {
        cout << curr->val << " ";
        curr = curr->next;
    }
    cout << endl;
}

int main() {
    // 构造二叉树
    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);

    // 将二叉树的节点插入链表
    ListNode* head = insertBinaryTreeToLinkedList(root);

    // 打印链表
    printLinkedList(head);

    return 0;
}