public static void DijkstrasAlgorithm(Dictionary<string, Dictionary<string, int>> graph, string start, string end)
{
    var shortestDistances = new Dictionary<string, int>();
    var predecessor = new Dictionary<string, string>();
    var nodes = new List<string>();

    foreach (var node in graph)
    {
        if (node.Key == start)
        {
            shortestDistances[node.Key] = 0;
        }
        else
        {
            shortestDistances[node.Key] = int.MaxValue;
        }

        nodes.Add(node.Key);
    }

    while (nodes.Count != 0)
    {
        nodes.Sort((node1, node2) => shortestDistances[node1].CompareTo(shortestDistances[node2]));

        var smallest = nodes[0];
        nodes.RemoveAt(0);

        if (smallest == end)
        {
            var path = new List<string>();
            while (predecessor.ContainsKey(smallest))
            {
                path.Add(smallest);
                smallest = predecessor[smallest];
            }

            path.Add(start);
            path.Reverse();

            Console.WriteLine("Shortest path is " + string.Join(" -> ", path));
            return;
        }

        if (shortestDistances[smallest] == int.MaxValue)
        {
            break;
        }

        foreach (var neighbor in graph[smallest])
        {
            var alt = shortestDistances[smallest] + neighbor.Value;
            if (alt < shortestDistances[neighbor.Key])
            {
                shortestDistances[neighbor.Key] = alt;
                predecessor[neighbor.Key] = smallest;
            }
        }
    }

    Console.WriteLine("Path does not exist!");
}