public IActionResult Details(string id)
        {
            var submissions = submissionsService.GetSubmissionsById(id)
                              .Select(x => new SubmissionViewModel
            {
                Id             = x.Id,
                AchievedResult = x.AchievedResult,
                MaxPoints      = x.Problem.Points,
                CreatedOn      = x.CreatedOn.ToString("dd/MM/yyyy"),
                Username       = x.User.Username
            }).ToList();

            string problemName = problemsService.GetProblems().Where(x => x.Id == id).Select(x => x.Name).FirstOrDefault();

            if (problemName == null)
            {
                return(this.Redirect("/"));
            }


            return(this.View(new SubmissionListViewModel {
                ProblemName = problemName, Submissions = submissions
            }));
        }