A Adjacency List representation of a Graph

adjacency-list.js

// The index of the element in the outer Array is the 'id' of the Node in the Graph.
// Each element in the outer Array contains the Set of IDs to which that Node is connected.
// 
// e.g. Node 0 has Edges to Nodes 1 and 2
//      Node 1 has no Edges
//      Node 2 has Edges to Nodes 0, 1 and 3
//      Node 3 only has an Edge to Node 2

let graphAsList = [
  [1, 2],
  [],
  [0, 1, 3],
  [2]
];

// A Map is another viable way to represent an Adjacency List
let graphAsMap = {
    0: [1, 2],
    1: [],
    2: [0, 1, 3],
    3: [2],
};