Given a reference of a node in a connected undirected graph, return a deep copy of the graph.
Sample Input:
[[2,4],[1,3],[2,4],[1,3]]
Sample Output:
[[2,4],[1,3],[2,4],[1,3]]
Hints
Hint 1
Use a hash map to track original to cloned nodes
Hint 2
Use DFS or BFS to traverse the graph
Hint 3
Create clones and establish connections
