一、 递归实现: 1*2* Definitionforbinary tree3*structTreeNode {4*intval;5* TreeNode *left;6* TreeNode *right;7* TreeNode(intx) : val(x), left(NULL), right(NULL) {}8*};9*/10classSolution {11public:12vector<vector<int> > levelOrder(TreeNode *root) {13vector<vector<int>>result...
node=queue[p][0]ifmax_dep <current_dep: ret.append([]) max_dep=current_dep ret[current_dep- 1].append(node.val)fornodein(node.left,node.right):ifnode: queue.append((node,current_dep+ 1)) q+= 1p+= 1returnret classSolution(object):deflevelOrder(self, root):""":type root: Tr...
Python 代码 fromcollectionsimportdeque# 定义二叉树节点classTreeNode:def__init__(self,val=0,left=None,right=None):self.val=valself.left=leftself.right=rightdeflevelOrder(root):# 如果根节点为空,返回空列表ifnotroot:return[]# 初始化队列和结果列表queue=deque([root])result=[]whilequeue:level_siz...
class Solution(object): def zigzagLevelOrder(self, root): tree = [] if not root: return tree curr_level = [root] direction = 'L' # print(type(root), type(curr_level)) # (<class 'precompiled.treenode.TreeNode'>, <type 'list'>) # print(curr_level) # 作为list,却并不能遍历整个...
这道题目跟上道题目很相似 Leetcode: Binary Tree Level Order Traversal ,唯一不同的就是返回结果是从子叶节点到根节点,所以我们只需要将结果翻转下就好了! 参考代码: /** * Definition for binary tree * struct TreeNode { * int val; * TreeNode *left; ...
Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example: Given binary tree [3,9,20,null,null,15,7], 代码语言:javascript 代码运行次数:0 运行 AI代码解释 ...
functionspiralOrder(matrix:number[][]):number[]{letx=0,y=0,n=matrix.length,m=matrix[0].length;// 绕圈遍历,每一次的最后一个作为下一次起点, 通过偏移量,每一轮的遍历前后各缩进+1// 偏移量从1开始目的是数组index从0开始letoffset=1,ret=[],gridNum=m*n;while(gridNum>1){letstartx=x,start...
这道题和LeetCode笔记:107. Binary Tree Level Order Traversal II是姊妹题,解题思路都是一样的,只是结果要求的顺序是反的,同样有两种方法,也就是经常说到的DFS深度优先遍历和BFS广度优先遍历。 BFS: 广度优先遍历就是一层层地攻略过去,把每一层的所有节点都记录下来再走向下一层。因为每层会有多个节点,不是简...
Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example: Given binary tree [3,9,20,null,null,15,7], 3 / 9 20 / 15 7 return its level order traversal as: ...
DFS代码参考地址:LeetCode Binary Tree Level Order Traversal 其他题目: Binary Tree Level Order Traversal II 层次遍历从低往root结点输出,如Given binary tree{3,9,20,#,#,15,7}, 3 / \ 9 20 / \ 15 7 return its level order traversal as: ...