Deep Copy, Deep Dive – Clone That Graph!
Clone Graph – Making a Perfect Copy Today’s problem is a classic graph challenge: deep copying a graph given the reference to one of its nodes. At first glance, it may seem like a straightforward copy-paste job—but in a connected undirected graph, cycles and shared references make it trickier than it looks! Let’s break it down! Best Data Structure for Solving It To tackle this, we use a HashMap (or Dictionary) to keep track of already cloned nodes. Why? Graphs can have cycles. Nodes can be shared across paths. Without tracking, we’d create duplicate nodes or go into infinite recursion. Different Approaches – Brute Force to Optimized 1. DFS Approach (Recursive) We use Depth-First Search to traverse and clone nodes recursively. class Solution { private Map<Node, Node> visited = new HashMap <>(); public Node cloneGraph (Node node) { if (node == null ) return null ; if (visited.containsKey(node)) return visited.get(node); ...