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 #.

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         / \         \_/

/** * Definition for undirected graph. * struct UndirectedGraphNode { *     int label; *     vector<UndirectedGraphNode *> neighbors; *     UndirectedGraphNode(int x) : label(x) {}; * }; */class Solution {public:    UndirectedGraphNode *cloneGraph(UndirectedGraphNode *node) {        queue<UndirectedGraphNode *> q;        set<UndirectedGraphNode *> s;        vector<UndirectedGraphNode *> v;        if(node == NULL) return NULL;        q.push(node);        v.push_back(node);        s.insert(node);        while(!q.empty())        {            UndirectedGraphNode *temp;            temp = q.front();            int n = temp->neighbors.size();            for(int i = 0; i < n; i++)            {                if(s.find(temp->neighbors[i]) == s.end())                {                    q.push(temp->neighbors[i]);                    v.push_back(temp->neighbors[i]);                    s.insert(temp->neighbors[i]);                }            }            q.pop();        }                int n = v.size();        vector<int> nums;        vector<UndirectedGraphNode *> clone;        for(int i = 0; i < n; i++)        {            nums.push_back(v[i]->label);            v[i]->label = i;            UndirectedGraphNode *NewNode = new UndirectedGraphNode(i);            clone.push_back(NewNode);        }                for(int i = 0; i < n; i++)        {            int m = v[i]->neighbors.size();            for(int j = 0; j < m; j++)            {                int num = v[i]->neighbors[j]->label;                clone[i]->neighbors.push_back(clone[num]);            }        }                for(int i = 0; i < n; i++)clone[i]->label = nums[i];        return clone[0];    }};