upgrade

vendor/graphp/algorithms/src/Eulerian.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace Graphp\Algorithms;
+
+class Eulerian extends BaseGraph
+{
+    /**
+     * check whether this graph has an eulerian cycle
+     *
+     * @return bool
+     * @uses ConnectedComponents::isSingle()
+     * @uses Degree::getDegreeVertex()
+     * @todo isolated vertices should be ignored
+     * @todo definition is only valid for undirected graphs
+     */
+    public function hasCycle()
+    {
+        $components = new ConnectedComponents($this->graph);
+        if ($components->isSingle()) {
+            $alg = new Degree($this->graph);
+
+            foreach ($this->graph->getVertices() as $vertex) {
+                // uneven degree => fail
+                if ($alg->getDegreeVertex($vertex) & 1) {
+                    return false;
+                }
+            }
+
+            return true;
+        }
+
+        return false;
+    }
+}