leetcode---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     / \     \_/

/** * Definition for undirected graph. * struct UndirectedGraphNode { *     int label; *     vector<UndirectedGraphNode *> neighbors; *     UndirectedGraphNode(int x) : label(x) {}; * }; */class Solution {public:    UndirectedGraphNode *cloneGraph(UndirectedGraphNode *node)     {        if(node == NULL)            return NULL;        queue<UndirectedGraphNode *> q;        map<UndirectedGraphNode*, UndirectedGraphNode*> m;        q.push(node);        while(!q.empty())        {            UndirectedGraphNode *nowNode = q.front();            q.pop();            if(!m.count(nowNode))            {                UndirectedGraphNode *newNode = new UndirectedGraphNode(nowNode->label);                m[nowNode] = newNode;            }            for(int i=0; i<nowNode->neighbors.size(); i++)            {                UndirectedGraphNode *neighNode = nowNode->neighbors[i];                if(!m.count(neighNode))                {                    UndirectedGraphNode *newNode = new UndirectedGraphNode(neighNode->label);                    m[neighNode] = newNode;                    q.push(neighNode);                }                m[nowNode]->neighbors.push_back(m[neighNode]);            }        }        return m[node];    }};