【LeetCode】133. Clone Graph

最新推荐文章于 2021-12-18 21:11:27 发布

原创最新推荐文章于 2021-12-18 21:11:27 发布 · 294 阅读

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本文介绍了一种使用深度优先搜索实现无向图克隆的方法。通过递归地复制每个节点及其邻居，确保了克隆图与原图结构一致。

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Description:

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 node 0 to both nodes 1 and 2.
Second node is labeled as 1. Connect node 1 to node 2.
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:

题目要求：克隆无向图

该题可采用深度优先算法一边遍历一边复制即可。

映射表m用来保存原图结点与克隆结点的对应关系。

映射表visited用来记录已经访问过的原图结点，防止循环访问。

队列q用于记录广度优先遍历的层次信息

Solutions：

class Solution {
public:
map<UndirectedGraphNode *, UndirectedGraphNode *> m;

UndirectedGraphNode *cloneGraph(UndirectedGraphNode *node)
{
if(node == NULL)
return NULL;

if(m.find(node) != m.end()) //if node is visited, just return the recorded nodeClone
return m[node];

UndirectedGraphNode *nodeClone = new UndirectedGraphNode(node->label);
m[node] = nodeClone;
for(int st = 0; st < node->neighbors.size(); st ++)
{
UndirectedGraphNode *temp = cloneGraph(node->neighbors[st]);
if(temp != NULL)
nodeClone->neighbors.push_back(temp);
}
return nodeClone;
}
};