面试题 04.03. 特定深度节点链表

缺乏、安全感 2022-12-21 03:07 112阅读 0赞

# 题目来源 #

[面试题 04.03. 特定深度节点链表][04.03.]

# 题目描述 #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poaXpoZW5nZ3Vhbg_size_16_color_FFFFFF_t_70_pic_center]

# 题目解析 #

/**
     * Definition for a binary tree node.
     * public class TreeNode {
     *     int val;
     *     TreeNode left;
     *     TreeNode right;
     *     TreeNode(int x) { val = x; }
     * }
     */
    /**
     * Definition for singly-linked list.
     * public class ListNode {
     *     int val;
     *     ListNode next;
     *     ListNode(int x) { val = x; }
     * }
     */
    class Solution {
        
    public ListNode[] listOfDepth(TreeNode tree) {
        
            if(tree == null){
        
                return null;
            }
            
            Queue<TreeNode> queue = new LinkedList<>();
            queue.add(tree);
            ListNode dummyHead = new ListNode(-1);
            LinkedList<ListNode> list = new LinkedList<>();
            while (!queue.isEmpty()){
        
                ListNode curr = dummyHead;
                
                int size = queue.size();
                for (int i = 0; i < size; i++){
        
                    TreeNode poll = queue.poll();
                    curr.next = new ListNode(poll.val);
                    curr = curr.next;
                    if (poll.left != null){
        
                        queue.offer(poll.left);
                    }
                    if (poll.right != null){
        
                        queue.offer(poll.right);
                    }
                }
    
                list.add(dummyHead.next);
            }
            
            ListNode[] res = new ListNode[list.size()];
            for (int i = 0; i < list.size(); i++){
        
                res[i] = list.get(i);
            }
            
            return res;
        }
    }

![在这里插入图片描述][20201113212236708.png_pic_center]

[04.03.]: https://leetcode-cn.com/problems/list-of-depth-lcci/
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poaXpoZW5nZ3Vhbg_size_16_color_FFFFFF_t_70_pic_center]: /images/20221120/9ba2a39c56924664a3f77849c35e16bb.png
[20201113212236708.png_pic_center]: /images/20221120/1e88f508410b4597a21de7ef45fa2345.png