Max and min components in a Graph using Breadth First Search in PHP

MaxMinComponentsinGraph.php

<?php
/**
 * Created by PhpStorm.
 * User: adriano
 * Date: 09/11/19
 * Time: 18:18
 */

class Vertex {

	private $data;
	private $edges = [];
	private $visited = false;

	public function __construct( $data ) {
		$this->data = $data;
	}

	public function getEdges() {
		return $this->edges;
	}

	public function addEdge( Vertex $edge ) {
		$this->edges[ $edge->getData() ] = $edge;
	}

	public function getData() {
		return $this->data;
	}

	public function setVisited() {
		$this->visited = true;
	}

	public function isVisited() {
		return $this->visited;
	}
}

function buildGraph( $gb ) {
	$graph = [];

	foreach( $gb as $key => $pair ) {
		$firstVertex = $graph[ $pair[0] ] ?? new Vertex( $pair[0] );
		$secondVertex = $graph[ $pair[1] ] ?? new Vertex( $pair[1] );

		if ( ! isset( $firstVertex->getEdges()[ $secondVertex->getData() ] ) ) {
			$firstVertex->addEdge( $secondVertex );
		}

		if ( ! isset( $secondVertex->getEdges()[ $firstVertex->getData() ] ) ) {
			$secondVertex->addEdge( $firstVertex );
		}

		if ( ! isset( $graph[ $firstVertex->getData() ] ) ) {
			$graph[ $firstVertex->getData() ] = $firstVertex;
		}

		if ( ! isset( $graph[ $secondVertex->getData() ] ) ) {
			$graph[ $secondVertex->getData() ] = $secondVertex;
		}
	}

	return $graph;
}

/*
 * Complete the componentsInGraph function below.
 */
function componentsInGraph($gb) {
	$graph = buildGraph( $gb );

	$queue = [];
	$smallest = 0;
	$highest = 0;

	foreach( $graph as $vertex ) {
		$numOfNodes = 0;

		if ( $vertex->isVisited() ) {
			continue;
		}

		$queue[] = $vertex;
		$numOfNodes++;

		$currentVertex = $vertex;

		while( $queue ) {
			foreach( $currentVertex->getEdges() as $edge ) {
				if ( $edge->isVisited() ) {
					continue;
				}

				$edge->setVisited();
				$numOfNodes++;
				$queue[] = $edge;
			}

			array_shift( $queue );
			$currentVertex->setVisited();
			$currentVertex = current( $queue );
		}

		if ( ! $highest || $highest < $numOfNodes ) {
			$highest = $numOfNodes;
		}

		if ( ! $smallest || $smallest > $numOfNodes ) {
			$smallest = $numOfNodes;
		}
	}

	print $smallest . ' ' . $highest;
}

componentsInGraph(
	[
		[ 5, 56 ],
		[ 4, 51 ],
		[ 2, 53 ],
		[ 8, 52 ],
		[ 5, 43 ],
		[ 2, 80 ],
		[ 5, 47 ],
		[ 4, 79 ],
		[ 3, 75 ],
		[ 1, 67 ],
		[ 7, 61 ],
		[ 2, 57 ],
		[ 5, 47 ],
		[ 4, 63 ],
		[ 10, 79 ],
		[ 1, 57 ],
		[ 4, 42 ],
		[ 8, 79 ],
		[ 6, 53 ],
		[ 3, 74 ],
		[ 7, 60 ],
		[ 10, 79 ],
		[ 5, 46 ],
		[ 3, 50 ],
		[ 6, 57 ],
		[ 8, 71 ],
		[ 6, 74 ],
		[ 10, 44 ],
		[ 9, 80 ],
		[ 7, 59 ],
		[ 7, 74 ],
		[ 6, 55 ],
		[ 3, 77 ],
		[ 3, 53 ],
		[ 5, 50 ],
		[ 9, 70 ],
		[ 4, 72 ],
		[ 5, 73 ],
		[ 6, 70 ],
		[ 7, 46 ],
	]
);