2020-08-01 09:11:19 +05:30
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class GraphUnweightedUndirectedAdjacencyList {
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2020-07-07 12:39:33 +05:30
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// Unweighted Undirected Graph class
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2023-10-03 23:08:19 +02:00
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constructor() {
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2020-07-07 12:39:33 +05:30
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this.connections = {}
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}
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2023-10-03 23:08:19 +02:00
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addNode(node) {
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2020-07-07 12:39:33 +05:30
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// Function to add a node to the graph (connection represented by set)
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this.connections[node] = new Set()
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}
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2023-10-03 23:08:19 +02:00
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addEdge(node1, node2) {
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2020-07-07 12:39:33 +05:30
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// Function to add an edge (adds the node too if they are not present in the graph)
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2023-10-03 23:08:19 +02:00
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if (!(node1 in this.connections)) {
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this.addNode(node1)
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}
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if (!(node2 in this.connections)) {
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this.addNode(node2)
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}
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2020-07-07 12:39:33 +05:30
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this.connections[node1].add(node2)
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this.connections[node2].add(node1)
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}
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2023-10-03 23:08:19 +02:00
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DFSComponent(components, node, visited) {
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2020-07-07 12:39:33 +05:30
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// Helper function to populate the visited set with the nodes in each component
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// adding the first visited node in the component to the array
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components.push(node)
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const stack = [node]
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// populating the visited set using DFS (Iterative)
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while (stack.length > 0) {
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const curr = stack.pop()
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visited.add(curr.toString())
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for (const neighbour of this.connections[curr].keys()) {
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2023-10-03 23:08:19 +02:00
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if (!visited.has(neighbour.toString())) {
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stack.push(neighbour)
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}
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2020-07-07 12:39:33 +05:30
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}
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}
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}
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2023-10-03 23:08:19 +02:00
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connectedComponents() {
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2020-07-07 12:39:33 +05:30
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// Function to generate the Connected Components
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// Result is an array containing 1 node from each component
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const visited = new Set()
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const components = []
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for (const node of Object.keys(this.connections)) {
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2023-10-03 23:08:19 +02:00
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if (!visited.has(node.toString())) {
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this.DFSComponent(components, node, visited)
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}
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2020-07-07 12:39:33 +05:30
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}
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return components
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}
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}
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2021-10-10 17:55:08 +02:00
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export { GraphUnweightedUndirectedAdjacencyList }
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// Example
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2020-07-07 12:39:33 +05:30
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2021-10-10 17:55:08 +02:00
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// const graph = new GraphUnweightedUndirectedAdjacencyList()
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// graph.addEdge(1, 2) // Component 1
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// graph.addEdge(3, 4) // Component 2
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// graph.addEdge(3, 5) // Component 2
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// const components = graph.connectedComponents()
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