public ActionResult GetUrl()
    {
        var action = GetBaseAction();
        if (SelectedDivisions.Any()) action.AddRouteValue("SelectedDisions", SelectedDivisions.ToArray());
        if (RoomId.HasValue) action.AddRouteValue("RoomId", RoomId.Value);
        if (TeacherId.HasValue) action.AddRouteValue("TeacherId", TeacherId.Value);
        if (Month.HasValue) action.AddRouteValue("Month", Month.Value);
        if (Year.HasValue) action.AddRouteValue("Year", Year.Value);
        if (Day.HasValue) action.AddRouteValue("Day", Day.Value);

        return action;
    }

String.Join(",", SelectedDivisions.ToArray())

var routeValues = new RouteValueDictionary();
            for (var i = 0; i < SelectedDivisions.Count; i++)
            {
                routeValues["SelectedDivisions[" + i + "]"] = SelectedDivisions[i];
            }
            action.AddRouteValues(routeValues);