#133 - Clone Graph - LeetCode JavaScript Solutions

#133 - Clone Graph

Problem Description

Given a reference of a node in a connected undirected graph.

Return a deep copy (clone) of the graph.

Each node in the graph contains a value (int) and a list (List[Node]) of its neighbors.

Test case format:

For simplicity, each node's value is the same as the node's index (1-indexed). For example, the first node with val == 1, the second node with val == 2, and so on. The graph is represented in the test case using an adjacency list.
An adjacency list is a collection of unordered lists used to represent a finite graph. Each list describes the set of neighbors of a node in the graph.
The given node will always be the first node with val = 1. You must return the copy of the given node as a reference to the cloned graph.

Solution

/**
 * // Definition for a Node.
 * function Node(val, neighbors) {
 *    this.val = val === undefined ? 0 : val;
 *    this.neighbors = neighbors === undefined ? [] : neighbors;
 * };
 */

/**
 * @param {Node} node
 * @return {Node}
 */
var cloneGraph = function(node) {
  const map = new Map();
  return node && cloneNode(node, map);
};

function cloneNode(node, map) {
  const cloned = new Node(node.val, node.neighbors);
  map.set(node.val, cloned);

  cloned.neighbors = node.neighbors && node.neighbors.map(n => {
    return map.get(n.val) || cloneNode(n, map);
  });

  return cloned;
}