标签：des style blog color io ar strong for div
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
/ \_/
题目意思是克隆一张图。
我的解题思路是 先用bfs遍历原来的图，把label和节点加入到map中。
然后新建一个复制节点的map，遍历原来map，第一遍遍历新建节点 加入到新map中，第二遍把邻节点list加到新节点中。
1 /** 2 * Definition for undirected graph. 3 * class UndirectedGraphNode { 4 * int label; 5 * List<UndirectedGraphNode> neighbors; 6 * UndirectedGraphNode(int x) { label = x; neighbors = new ArrayList<UndirectedGraphNode>(); } 7 * }; 8 */ 9 public class Solution { 10 private void bfs(UndirectedGraphNode node,HashMap<Integer, UndirectedGraphNode> visitedmap) { 11 12 LinkedList<UndirectedGraphNode> tovisitList = new LinkedList<>(); 13 14 tovisitList.addLast(node); 15 while (!tovisitList.isEmpty()) { 16 UndirectedGraphNode first = tovisitList.getFirst(); 17 tovisitList.removeFirst(); 18 visitedmap.put(first.label, first); 19 for (UndirectedGraphNode undirectedGraphNode : first.neighbors) { 20 if (!visitedmap.containsKey(undirectedGraphNode.label)&&!tovisitList.contains(undirectedGraphNode)) { 21 tovisitList.addLast(undirectedGraphNode); 22 } 23 } 24 } 25 26 } 27 public UndirectedGraphNode cloneGraph(UndirectedGraphNode node) { 28 if (node==null) { 29 return null; 30 } 31 UndirectedGraphNode newGraph = new UndirectedGraphNode(node.label); 32 if (node.neighbors.isEmpty()) { 33 return newGraph; 34 } 35 HashMap<Integer, UndirectedGraphNode> visitedmap=new HashMap<>(); 36 HashMap<Integer, UndirectedGraphNode> copymap=new HashMap<>(); 37 bfs(node, visitedmap); 38 for (Integer key : visitedmap.keySet()) { 39 copymap.put(key, new UndirectedGraphNode(key)); 40 } 41 for (Integer key : visitedmap.keySet()) { 42 for (UndirectedGraphNode tnode : visitedmap.get(key).neighbors) { 43 copymap.get(key).neighbors.add(copymap.get(tnode.label)); 44 } 45 } 46 return copymap.get(node.label); 47 48 } 49 50 51 }
标签：des style blog color io ar strong for div
原文地址：http://www.cnblogs.com/birdhack/p/3973589.html
