摘要：
Given a non-negative number represented as a singly linked list of digits, plus one to the number. The digits are stored such that the most significan 阅读全文
摘要：
One way to serialize a binary tree is to use pre-order traversal. When we encounter a non-null node, we record the node's value. If it is a null node, 阅读全文
摘要：
Clone an undirected graph. Each node in the graph contains a label and a list of its neighbors. OJ's undirected graph serialization: Nodes are labeled 阅读全文
摘要：
Given a set of distinct positive integers, find the largest subset such that every pair (Si, Sj) of elements in this subset satisfies: Si % Sj = 0 or 阅读全文