标签：width mat map graph object 两种方法 算法 bsp The
Given a reference of a node in a connected undirected graph, return a deep copy (clone) of the graph. Each node in the graph contains a val (int) and a list (List[Node]) of its neighbors.
Example:
Input:
{"$id":"1","neighbors":[{"$id":"2","neighbors":[{"$ref":"1"},{"$id":"3","neighbors":[{"$ref":"2"},{"$id":"4","neighbors":[{"$ref":"3"},{"$ref":"1"}],"val":4}],"val":3}],"val":2},{"$ref":"4"}],"val":1}
Explanation:
Node 1‘s value is 1, and it has two neighbors: Node 2 and 4.
Node 2‘s value is 2, and it has two neighbors: Node 1 and 3.
Node 3‘s value is 3, and it has two neighbors: Node 2 and 4.
Node 4‘s value is 4, and it has two neighbors: Node 1 and 3.
Note:
Soulution:
使用DFS和BFS即可
两种方法在leetcode中都能通过，但在牛客中，BFS使用的而外空间超出限制，所以只能使用DFS
1 struct UndirectedGraphNode { 2 int label; 3 vector<UndirectedGraphNode *> neighbors; 4 UndirectedGraphNode(int x) : label(x) {}; 5 }; 6 7 //DFS 8 class Solution01 { 9 public: 10 UndirectedGraphNode *cloneGraph(UndirectedGraphNode *node) { 11 unordered_map<UndirectedGraphNode*, UndirectedGraphNode*>mapR; 12 return helper(node, mapR); 13 } 14 UndirectedGraphNode* helper(UndirectedGraphNode*node, unordered_map<UndirectedGraphNode*, UndirectedGraphNode*>&mapR) 15 { 16 if (node == nullptr)return nullptr; 17 if (mapR.find(node) != mapR.end())//旧节点 18 return mapR[node]; 19 UndirectedGraphNode* res = new UndirectedGraphNode(node->label);//新节点 20 mapR[node] = res; 21 for (auto a : node->neighbors) 22 res->neighbors.push_back(helper(a, mapR)); 23 return res; 24 } 25 }; 26 //BFS 27 class Solution02 { 28 public: 29 UndirectedGraphNode *cloneGraph(UndirectedGraphNode *node) { 30 queue<UndirectedGraphNode*>qNode; 31 qNode.push(node); 32 unordered_map<UndirectedGraphNode*, UndirectedGraphNode*>mapR; 33 UndirectedGraphNode *res = new UndirectedGraphNode(node->label); 34 mapR[node] = res; 35 while (!qNode.empty()) 36 { 37 UndirectedGraphNode *p = qNode.front(); 38 qNode.pop(); 39 for (auto a : p->neighbors) 40 { 41 if (mapR.find(a) == mapR.end())//新节点 42 { 43 qNode.push(a);//加入 44 mapR[a] = new UndirectedGraphNode(a->label);//新节点 45 } 46 mapR[p]->neighbors.push_back(mapR[a]);//连接节点 47 } 48 } 49 return res; 50 } 51 };
标签：width mat map graph object 两种方法 算法 bsp The
原文地址：https://www.cnblogs.com/zzw1024/p/11839160.html
