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Feature #2: Copy Connections

Explore how to clone a graph representing Facebook user connections by using depth-first traversal and hash tables. Understand the process of copying nodes and edges to replicate friend circles and how to handle cycles efficiently, preparing you to solve similar graph cloning problems in coding interviews.

Description

After identifying every user’s friend circles, we need to duplicate this data to Instagram’s servers so it can be easily accessed and modified there as well. As the user’s name can be the same, so every user on Facebook gets assigned a unique id. Each Facebook user’s connections are represented and stored in a graph-like structure. We will first have to make an exact copy of this structure before storing it on Instagram’s servers.

Let’s say we want to duplicate the data for the following users:

For each user, we’ll be provided with a node and its information. This node will point to other nodes, and from that one node, we need to reach and make an exact clone of every other node. An edge between two nodes means that they are friends with each other. A bi-directional edge means that both users follow each ...