DepthFirstSearchIterative.js

class GraphUnweightedUndirected {
 // Unweighted Undirected Graph class
 constructor() {
 this.connections = {}
 }

 addNode(node) {
 // Function to add a node to the graph (connection represented by set)
 this.connections[node] = new Set()
 }

 addEdge(node1, node2) {
 // Function to add an edge (adds the node too if they are not present in the graph)
 if (!(node1 in this.connections)) {
 this.addNode(node1)
 }
 if (!(node2 in this.connections)) {
 this.addNode(node2)
 }
 this.connections[node1].add(node2)
 this.connections[node2].add(node1)
 }

 DFSIterative(node, value) {
 // DFS Function to search if a node with the given value is present in the graph
 const stack = [node]
 const visited = new Set()
 while (stack.length > 0) {
 const currNode = stack.pop()
 // if the current node contains the value being searched for, true is returned
 if (currNode === value) {
 return true
 }
 // adding the current node to the visited set
 visited.add(currNode)
 // adding neighbours in the stack
 for (const neighbour of this.connections[currNode]) {
 if (!visited.has(neighbour)) {
 stack.push(neighbour)
 }
 }
 }
 return false
 }
}

export { GraphUnweightedUndirected }

// Example

// const graph = new GraphUnweightedUndirected()
// graph.addEdge(1, 2)
// graph.addEdge(2, 3)
// graph.addEdge(2, 4)
// graph.addEdge(3, 5)
// graph.DFSIterative(5, 1)
// graph.DFSIterative(5, 100)