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相同的树

Check whether two binary trees are identical by comparing structure and node values using DFS or BFS traversal strategie…

对称二叉树

Determine if a binary tree is symmetric by comparing left and right subtrees using DFS or BFS traversal techniques effic…

二叉树的层序遍历

Perform a level order traversal on a binary tree using BFS to return node values level by level.

二叉树的锯齿形层序遍历

Traverse a binary tree in zigzag level order, alternating directions at each depth using BFS and state tracking techniqu…

二叉树的最大深度

Find the maximum depth of a binary tree using traversal techniques to track the longest path from root to leaf.

二叉树的层序遍历 II

Return a bottom-up level order traversal of a binary tree, processing nodes left to right while tracking each level accu…

二叉树的最小深度

Find the minimum depth of a binary tree, which is the shortest path from the root node to the nearest leaf node.

路径总和

Determine if a binary tree has a root-to-leaf path where the sum of node values equals a given target sum, using DFS or …

填充每个节点的下一个右侧节点指针

Connect each node across every level by reusing established next links to traverse a perfect binary tree without extra q…

填充每个节点的下一个右侧节点指针 II

Populate each next pointer in a binary tree to its immediate right node, handling nulls and uneven levels efficiently us…

单词接龙 II

Find all shortest transformation sequences from beginWord to endWord using a dictionary, leveraging backtracking search …

单词接龙

Find the shortest transformation sequence from a start word to an end word, with each word in the sequence differing by …

被围绕的区域

Transform the matrix in-place by marking regions surrounded by 'X' as 'X', while keeping border-adjacent 'O's intact.

克隆图

Clone Graph involves cloning a graph using DFS, focusing on graph traversal and neighbor management using hash tables.

二叉树的右视图

The Binary Tree Right Side View problem asks you to return the visible nodes from the right side of a binary tree, trave…

岛屿数量

Count the number of distinct islands in a binary grid using array traversal combined with depth-first search exploration…

课程表

Determine if all courses can be completed by analyzing prerequisite dependencies using indegree tracking and topological…

课程表 II

Solve the 'Course Schedule II' problem using graph indegree and topological ordering, utilizing DFS or BFS to find the c…

翻转二叉树

Invert Binary Tree swaps every node's left and right children using tree traversal, with recursive DFS or iterative BFS …

完全平方数

Perfect Squares asks for the least number of perfect squares summing to a given integer n using dynamic programming or B…

二叉树的序列化与反序列化

This problem asks to serialize and deserialize a binary tree, requiring an efficient approach to handle traversal and st…

删除无效的括号

Remove the minimum number of invalid parentheses to generate all possible valid strings efficiently using backtracking a…

最小高度树

Identify all roots of a tree that produce minimum height using graph indegree analysis and topological trimming.

零钱兑换

Find the minimum number of coins needed to reach a target amount using dynamic programming state transitions efficiently…