Clone an undirected graph. Each node in the graph contains a label and a list of its neighbors.
Nodes are labeled uniquely.
We use# as a separator for each node, and , as a separator for node label and each neighbor of the node.
As an example, consider the serialized graph {0,1,2#1,2#2,2}.
The graph has a total of three nodes, and therefore contains three parts as separated by #.
0. Connect node 0 to both nodes 1 and 2.1. Connect node 1 to node 2.2. Connect node 2 to node 2 (itself), thus forming a self-cycle.
Visually, the graph looks like the following:
1
/ / 0 --- 2
/ \_/
Reference: https://www.cnblogs.com/springfor/p/3874591.html
/** * Definition for undirected graph. * class UndirectedGraphNode { * int label; * List<UndirectedGraphNode> neighbors; * UndirectedGraphNode(int x) { label = x; neighbors = new ArrayList<UndirectedGraphNode>(); } * }; */ public class Solution { public UndirectedGraphNode cloneGraph(UndirectedGraphNode node) { if(node == null){ return null; } //queue Queue<UndirectedGraphNode> queue = new LinkedList<>(); //map Map<UndirectedGraphNode, UndirectedGraphNode> map = new HashMap<>(); UndirectedGraphNode head = new UndirectedGraphNode(node.label); map.put(node, head); queue.add(node); while(!queue.isEmpty()){ UndirectedGraphNode curnode = queue.poll(); //check each neighbor for(UndirectedGraphNode aneighbor: curnode.neighbors){ //if not visited,then add to queue if(!map.containsKey(aneighbor)){ queue.add(aneighbor); UndirectedGraphNode newneighbor = new UndirectedGraphNode(aneighbor.label); map.put(aneighbor, newneighbor); } map.get(curnode).neighbors.add(map.get(aneighbor)); } } return head; } }
LeetCode-Microsoft-Clone Graph
原文：https://www.cnblogs.com/incrediblechangshuo/p/8970640.html