/** * It verifies if the graph is or not regular. * * @param g * @return true, if the graph is regular; or false, on the contrary. */ public static function isRegular(Graph $g) { $allVertices = $g->getVertexSet(); $degree = -1; foreach ($allVertices as $vertex) { if ($degree != -1) { if ($g->degreeOf($vertex) != $degree) { return false; } } else { $degree = $g->degreeOf($vertex); } } return true; }