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 node0
to both nodes1
and2
. - Second node is labeled as
1
. Connect node1
to node2
. - Third node is labeled as
2
. Connect node2
to node2
(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;
unordered_map<UndirectedGraphNode *,UndirectedGraphNode *> nodeMap;
queue<UndirectedGraphNode *> visit;
visit.push(node);
UndirectedGraphNode * copyNode = new UndirectedGraphNode(node -> label);
nodeMap[node] = copyNode;
while(visit.size() > 0){
UndirectedGraphNode *cur = visit.front();
visit.pop();
for(int i = 0;i < cur -> neighbors.size();i ++){
UndirectedGraphNode *neighbor = cur -> neighbors[i];
if(nodeMap.find(neighbor) == nodeMap.end()){
UndirectedGraphNode *neighborCopy = new UndirectedGraphNode(neighbor -> label);
nodeMap[cur] -> neighbors.push_back(neighborCopy);
nodeMap[neighbor] = neighborCopy;
visit.push(neighbor);
}else{
nodeMap[cur] ->neighbors.push_back(nodeMap[neighbor]);
}
}
}
return copyNode;
}
};