NodeNeighbors.js

// https://en.wikipedia.org/wiki/Neighbourhood_(graph_theory)

class Graph {
 // Generic graph: the algorithm works regardless of direction or weight
 constructor() {
 this.edges = []
 }

 addEdge(node1, node2) {
 // Adding edges to the graph
 this.edges.push({
 node1,
 node2
 })
 }

 nodeNeighbors(node) {
 // Returns an array with all of the node neighbors
 const neighbors = new Set()
 for (const edge of this.edges) {
 // Checks if they have an edge between them and if the neighbor is not
 // already in the neighbors array
 if (edge.node1 === node && !neighbors.has(edge.node2)) {
 neighbors.add(edge.node2)
 } else if (edge.node2 === node && !neighbors.has(edge.node1)) {
 neighbors.add(edge.node1)
 }
 }
 return neighbors
 }
}

export { Graph }

// const graph = new Graph()
// graph.addEdge(1, 2)
// graph.addEdge(2, 3)
// graph.addEdge(3, 5)
// graph.addEdge(1, 5)
// graph.nodeNeighbors(1)