fromcollectionsimportdeque# Definition for a binary tree node.classTreeNode:def__init__(self, x): self.val = x self.left =Noneself.right =Nonedeflevel_order_tree(root, result):ifnotroot:return# 这里借助python的双向队列
# 二叉树节点定义classTreeNode:def__init__(self,val):self.val=val self.left=None self.right=None # 二叉树的DFS遍历 defdfs_binary_tree(root):ifroot is None:returnprint(root.val,end=' ')dfs_binary_tree(root.left)dfs_binary_tree(root.right)# 构造二叉树 root=TreeNode(1)root.left=Tree...
LeetCode 103. Binary Tree Zigzag Level Order Traversal之字形层序遍历 LeetCode 199. Binary Tree Right Side View找每一层的最右结点 LeetCode 515. Find Largest Value in Each Tree Row计算每一层的最大值 LeetCode 637. Average of Levels in Binary Tree计算每一层的平均值 对于最短路径问题,还有两道...
returndepth ifnodeindead: continue else: # neighbors(node) 生成器对象 forneiinneighbors(node): ifneinotinseen: seen.add(nei) queue.append((nei, depth+1)) return-1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 # Definition for a binary tree node. # clas...
for 节点 in cur的所有相邻节点: if 该节点有效且未被访问过: queue.push(该节点) } level ++; } 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 上面两个是通用模板,在任何题目中都可以用,是要记住的! 应用一:层序遍历 LeetCode 102. Binary Tree Level Order Traversal 二叉树的层序遍历...
问题1:Symmetric Tree 问题2:Vertical Order Traversal of a Binary Tree 问题3:Word Ladder 适用范围 当答案距离根节点近,并且可以一层一层进行探索的情况。 最短路径问题:BFS可以用于寻找无权图中两个节点之间的最短路径。由于BFS会逐层遍历图,因此当搜索到目标节点时,它一定是经过的最少边数的路径之一,因此可...
代码(Python3) # Definition for a binary tree node. # class TreeNode: # def __init__(self, val=0, left=None, right=None): # self.val = val # self.left = left # self.right = right class Solution: def levelOrder(self, root: Optional[TreeNode]) -> List[List[int]]: ans: Lis...
这里借用来自社区大佬的Python实现, 非常的优雅: leetcode 上也有这三种遍历的题目, 因为不是本文重点,所以就用递归简单实现一下: 144 前序遍历的简单实现 - medium 给定一个二叉树,返回它的 _前序 _遍历。 代码语言:javascript 代码运行次数:0 运行
r=Node(root.val)forcinroot.children:child=self.cloneTree(c)r.children.append(child)returnr 84 ms 17.5 MB 2.2 BFS 使用2个队列,同步进行出入队即可 代码语言:javascript 代码运行次数:0 运行 AI代码解释 classSolution{public:Node*cloneTree(Node*root){if(!root)returnroot;Node*r=newNode(root->val...
These Pre-cooked and well-tested codes help to implement larger hackathon problems in lesser time. DFS, BFS, LCA, LCS, Segment Tree, Sparce Table, All Pair Shortest Path, Binary Search, Matching and many more ... java hashing algorithms graph-algorithms concurrency competitive-programming data...