From f6f60fe3ac3d6d460249493421466213a4930f49 Mon Sep 17 00:00:00 2001
From: Felix Hillingshaeuser <felix@mxcore.de>
Date: Thu, 4 Jul 2024 15:43:57 +0200
Subject: [PATCH] add function to get a list of all vertices in the graph

---
 graph.go      | 11 +++++++++++
 graph_test.go | 19 ++++++++++++++++++-
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/graph.go b/graph.go
index 29a033d..a7870b6 100644
--- a/graph.go
+++ b/graph.go
@@ -225,3 +225,14 @@ func (g Graph) validate() error {
 	}
 	return nil
 }
+
+// GetVertices returns all indexes of all vertices
+func (g Graph) GetVertices() []int {
+	var vertices []int
+	for idx, vertex := range g.vertexArcs {
+		if vertex != nil {
+			vertices = append(vertices, idx)
+		}
+	}
+	return vertices
+}
diff --git a/graph_test.go b/graph_test.go
index 879916e..0990804 100644
--- a/graph_test.go
+++ b/graph_test.go
@@ -1,6 +1,9 @@
 package dijkstra
 
-import "testing"
+import (
+	"reflect"
+	"testing"
+)
 
 func TestGetVertex(t *testing.T) {
 	g := NewGraph()
@@ -74,3 +77,17 @@ func TestValidateCorrect(t *testing.T) {
 		}
 	}
 }
+
+func TestGetVertices(t *testing.T) {
+	g := NewGraph()
+	g.AddEmptyVertex(0)
+	expectedResult := []int{0}
+	if !reflect.DeepEqual(g.GetVertices(), expectedResult) {
+		t.Errorf("Graph should have vertices [0] but has %v", g.GetVertices())
+	}
+	g.AddEmptyVertex(4)
+	expectedResult = []int{0, 4}
+	if !reflect.DeepEqual(g.GetVertices(), expectedResult) {
+		t.Errorf("Graph should have vertices [0,4] but has %v", g.GetVertices())
+	}
+}