Problem: Clone Graph

You are given a reference to a single node in an undirected, connected graph. Your task is to create a deep copy of the graph starting from the given node. A deep copy means creating a new instance of every node in the graph with the same data and edges as the original graph, such that changes in the copied graph do not affect the original graph.

Each node in the graph contains two properties:

• data: The value of the node, which is the same as its index in the adjacency list.

• neighbors: A list of connected nodes, representing all the nodes directly linked to this node.

However, in the test cases, a graph is represented as an adjacency list to understand node relationships, where each index in the list represents a node (using 1-based indexing). For example, for $[[2, 3], [1, 3], [1, 2]]$, there are three nodes in the graph:

$1^{st}$ node (data = $1$): Neighbors are $2^{nd}$ node (data = $2$) and $3^{rd}$ node (data = $3$).

$2^{nd}$ node (data = $2$): Neighbors are $1^{st}$ node (data = $1$) and $3^{rd}$ node (data = $3$).

$3^{rd}$ node (data = $3$): Neighbors are $1^{st}$ node (data = $1$) and $2^{nd}$ node (data = $2$).

The adjacency list will be converted to a graph at the backend and the first node of the graph will be passed to your code.

Constraints:

• $0 \leq$ Number of nodes $\leq 100$

• $1\leq$ Node.data $\leq 100$

• Node.data is unique for each node.

• The graph is undirected, i.e., there are no self-loops or repeated edges.

• The graph is connected, i.e., any node can be visited from a given node.