无向图复制

Clone an undirected graph. Each node in the graph contains alabeland 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 as0. Connect node0to both nodes1and2.
2. Second node is labeled as1. Connect node1to node2.
3. Third node is labeled as2. Connect node2to node2(itself), thus forming a self-cycle.

 

Visually, the graph looks like the following:

       1
      / \
     /   \
    0 --- 2
         / \
         \_/

 采用深度优先遍历方法，利用一个map结构的数据记录复制的节点，使原始节点和复制节点一一对应。

/**
* Definition for undirected graph.
* struct UndirectedGraphNode {
* int label;
* vector<UndirectedGraphNode *> neighbors;
* UndirectedGraphNode(int x) : label(x) {};
* };
*/
class Solution {
public:
UndirectedGraphNode *clone(UndirectedGraphNode *node,map<UndirectedGraphNode *,UndirectedGraphNode *>&visit)
{
　　if(visit.find(node)!=visit.end()) return visit[node];
　　UndirectedGraphNode * nnode=new UndirectedGraphNode(node->label);
　　vector<UndirectedGraphNode *>::iterator it=node->neighbors.begin();
　　for(;it!=node->neighbors.end();it++)
　　{
　　　　nnode->neighbors.push_back(*it);

　　}
　　visit[node]=nnode;
　　return visit[node];

}
　　UndirectedGraphNode *cloneGraph(UndirectedGraphNode *node) {
　　if(node==NULL)
　　　　return NULL;
　　map<UndirectedGraphNode *,UndirectedGraphNode *>visit;
　　return clone(node,visit);
}