133. Clone Graph

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 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 #.

First node is labeled as 0. Connect node 0 to both nodes 1 and 2.
Second node is labeled as 1. Connect node 1 to node 2.
Third node is labeled as 2. Connect node 2 to node 2 (itself), thus forming a self-cycle.
Visually, the graph looks like the following:

       1      / \     /   \    0 --- 2         / \         \_/

code

/** * Definition for undirected graph. * public class UndirectedGraphNode { *     public int label; *     public IList<UndirectedGraphNode> neighbors; *     public UndirectedGraphNode(int x) { label = x; neighbors = new List<UndirectedGraphNode>(); } * }; */public class Solution {    private Dictionary<int,UndirectedGraphNode> dict = new Dictionary<int,UndirectedGraphNode>();    public UndirectedGraphNode CloneGraph(UndirectedGraphNode node) {        if(node==null) return node;                if(dict.ContainsKey(node.label))            return dict[node.label]; //self-cycle        UndirectedGraphNode clonenode = new UndirectedGraphNode(node.label);        dict.Add(node.label,clonenode);        foreach(var item in node.neighbors){ //add neighbors node            clonenode.neighbors.Add(CloneGraph(item));        }        return clonenode;    }}