[LeetCode] 133. Clone Graph

Clone an undirected graph. Each node in the graph contains a label and a list of its neighbors.

class Solution {public:    UndirectedGraphNode *cloneGraph(UndirectedGraphNode *node) {        return node == nullptr ? nullptr : DFS(node);    }private:    unordered_map<int, UndirectedGraphNode *> ToCopied;    UndirectedGraphNode *DFS(UndirectedGraphNode *node) {        UndirectedGraphNode *copiednode = new UndirectedGraphNode(node->label);        ToCopied[node->label] = copiednode;        for (auto neighbor : node->neighbors) {            if (ToCopied.find(neighbor->label) == ToCopied.end()) {                copiednode->neighbors.push_back(DFS(neighbor));            } else {                copiednode->neighbors.push_back(ToCopied[neighbor->label]);            }        }        return copiednode;    }};