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 node0to both nodes1and2. - Second node is labeled as
1. Connect node1to node2. - Third node is labeled as
2. Connect node2to node2(itself), thus forming a self-cycle.
Visually, the graph looks like the following:
1
/ \
/ \
0 --- 2
/ \
\_/
cpp代码如下：
class Solution {
public:
UndirectedGraphNode *cloneGraph(UndirectedGraphNode *node) {
if(node==NULL)return NULL;
map<UndirectedGraphNode*,UndirectedGraphNode*> quick_find;
set<UndirectedGraphNode*> visited;
queue<UndirectedGraphNode*> traverse_queue;
quick_find[node]=new UndirectedGraphNode(node->label);
traverse_queue.push(node);
while(!traverse_queue.empty()){
UndirectedGraphNode* tmp=traverse_queue.front();
traverse_queue.pop();
if(visited.count(tmp)!=0)continue;
UndirectedGraphNode* n=quick_find.find(tmp)->second;
for(vector<UndirectedGraphNode*>::iterator p=tmp->neighbors.begin();p!=tmp->neighbors.end();++p){
map<UndirectedGraphNode*,UndirectedGraphNode*>::iterator q=quick_find.find(*p);
if(q!=quick_find.end()){
n->neighbors.push_back(q->second);
}else{
UndirectedGraphNode* t=new UndirectedGraphNode((*p)->label);
quick_find[*p]=t;
n->neighbors.push_back(t);
}
traverse_queue.push(*p);
}
visited.insert(tmp);
}
return quick_find[node];
}
};