Understanding

Given a reference of a node in a connected undirected graph, return a deep copy (clone) of the graph. Each node in the graph contains a val (int) and a list (List[Node]) of its neighbors. [Read More]

You need to find the largest value in each row of a binary tree. [Read More]

Given a binary tree, find the leftmost value in the last row of the tree. [Read More]

命令 [Read More]

Remove the minimum number of invalid parentheses in order to make the input string valid. Return all possible results. [Read More]

Description [Read More]