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 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 / \ \_/
思路:
思路类似上题,用一个map来保存新旧graph节点的对应关系
代码:
1 UndirectedGraphNode *clone(UndirectedGraphNode *node, map<int,UndirectedGraphNode*> &table) 2 { 3 if(node==NULL) 4 return NULL; 5 6 if(table.find(node->label)!=table.end()) 7 return table[node->label]; 8 9 UndirectedGraphNode *newnode=new UndirectedGraphNode(node->label); 10 table[newnode->label]=newnode; 11 12 for(int i=0;i<node->neighbors.size();i++) 13 { 14 UndirectedGraphNode *neighbor=clone(node->neighbors[i],table); 15 newnode->neighbors.push_back(neighbor); 16 } 17 18 return newnode; 19 } 20 21 UndirectedGraphNode *cloneGraph(UndirectedGraphNode *node) { 22 // Note: The Solution object is instantiated only once and is reused by each test case. 23 //keep a hash table to check whether this node is visited or not 24 map<int,UndirectedGraphNode*> visitTable; 25 return clone(node,visitTable); 26 }