LeetCode OJ Clone Graph

Clone an undirected graph. Each node in the graph contains a label and a list of itsneighbors.

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#.

1. First node is labeled as 0. Connect node 0 to both nodes 1 and 2.
2. Second node is labeled as 1. Connect node 1 to node 2.
3. 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         / \         \_/

看了discuss，感觉像是用bfs将图遍历一遍。

class Solution {  public:    UndirectedGraphNode *cloneGraph(UndirectedGraphNode *node) {        if (node == NULL) return node;        queue<UndirectedGraphNode * > q;        map<int, UndirectedGraphNode * > m;  // store the node made to check if a node exists        q.push(node);  // store the node existed to bfs(my thought)        while (!q.empty()) {            UndirectedGraphNode * temp = q.front();            q.pop();            if (m.find(temp->label) == m.end()) {  // it is new node                m[temp->label] = new UndirectedGraphNode(temp->label);            }            map<int, UndirectedGraphNode * >::iterator tempMade = m.find(temp->label);  // find the corresponding node made            for (int i = 0; i < temp->neighbors.size(); i++) {                map<int, UndirectedGraphNode * >::iterator son = m.find(temp->neighbors[i]->label);                UndirectedGraphNode * newSon = son->second;  // ready for pushing back, if son is end(), newSon would be changed later                if (son == m.end()) {  // new node                    newSon = new UndirectedGraphNode(temp->neighbors[i]->label);  // make a new one                    m[temp->neighbors[i]->label] = newSon;  // the new node now is an old one                    q.push(temp->neighbors[i]);                }                tempMade->second->neighbors.push_back(newSon);            }        }        return m.find(node->label)->second;    }};