public class ScoreBasedDifficultySetting
    {
        public Difficulty DifficultyLevel { get; set; }
        public int MinScore { get; set; }
        public int MaxScore { get; set; }

        public ScoreBasedDifficultySetting(int min, int max, Difficulty difficultyLevel)
        {
            MinScore = min;
            MaxScore = max;
            DifficultyLevel = difficultyLevel;
        }
    }

    public class ScoreBasedDifficultyManager
    {
        public List<ScoreBasedDifficultySetting> DifficultySettings;
        public ScoreBasedDifficultyManager(List<ScoreBasedDifficultySetting> difficultySettings)
        {
            DifficultySettings = difficultySettings;
        }

        public Difficulty GetCurrentDifficulty(int score)
        {
            foreach (ScoreBasedDifficultySetting setting in DifficultySettings)
            {
                if (score >= setting.MinScore && score <= setting.MaxScore)
                {
                    return setting.DifficultyLevel;
                }
            }

            throw new NoValidDifficultyException();
        }
    }

    public enum Difficulty
    {
        Easy,
        Medium,
        Hard
    }