摘要：
Given an directed graph, a topological order of the graph nodes is defined as follow: For each directed edge A -> B in graph, A must before B in the o 阅读全文
摘要：
Given a undirected graph, a node and a target, return the nearest node to given node which value of it is target, return NULL if you can't find. There 阅读全文
摘要：
Clone an undirected graph. Each node in the graph contains a label and a list of its neighbors. How we serialize an undirected graph: Nodes are labele 阅读全文