Title: Clone Graph Source: leetcode.com Clone an undirected graph. Each node in the graph contains a label and a list of its neighbors. Nodes are labeled uniquely. Java solution Java /* https://leetcode.com/problems/clone-graph/ */ import java.util.HashMap; import java.util.List; import java.util.ArrayList; public class CloneGraph { public UndirectedGraphNode cloneGraph(UndirectedGraphNode node) { if(node==null) return null; HashMap<Integer, UndirectedGraphNode> visited = ...