【题目】
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 / \_/
【题意】
复制无向图。无向图中每个点有一个值唯一的label和邻接节点的label集合
【思路】
DFS或者BFS遍历无向图完成赋值
【注意】本题中使用malloc创建节点会报RUNTIME ERROR错误,必须用new创建节点
【代码】
/** * 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; queue<UndirectedGraphNode*> qe; queue<UndirectedGraphNode*> qe_copy; map<int, UndirectedGraphNode*> createdMap; //已经复制的节点 //创建第一个节点 //注意本题使用(UndirectedGraphNode*)malloc(sizeof(UndirectedGraphNode))会RUNTIME ERROR UndirectedGraphNode * newFirstNode = new UndirectedGraphNode(node->label); qe.push(node); qe_copy.push(newFirstNode); createdMap[node->label]=newFirstNode; while(!qe.empty()){ UndirectedGraphNode * qe_top = qe.front(); qe.pop(); UndirectedGraphNode * qe_copy_top = qe_copy.front();qe_copy.pop(); //创建邻接节点 int neighborsSize = qe_top->neighbors.size(); for(int i=0; i<neighborsSize; i++){ node = qe_top->neighbors[i]; //判断当前节点是否已经创建过 if(createdMap[node->label]!=NULL){ //如果已经创建了,直接从createdmap中取即可 qe_copy_top->neighbors.push_back(createdMap[node->label]); } else{ //如果还没创建,则创建新节点 //注意本题使用(UndirectedGraphNode*)malloc(sizeof(UndirectedGraphNode))会RUNTIME ERROR UndirectedGraphNode * node_copy = new UndirectedGraphNode(node->label); qe.push(node); qe_copy.push(node_copy); createdMap[node->label]=node_copy; //添加到qe_copy_top的邻接节点 qe_copy_top->neighbors.push_back(node_copy); } } } return newFirstNode; } };
LeetCode: Clone Graph [133]
时间: 2024-10-27 12:31:14