public void Puzzle_1A()
            {
                var input = PuzzleInputs.Puzzle1;

                var finder = new FactorFinder
                {
                    Candidates = input
                };

                var result = finder.FindTwoCandidatesThatSumTo(2020).ToArray();

                Assert.Equal(2020, result[0] + result[1]);
                Assert.Equal(1, result[0] * result[1]);
            }
            public void Should_find_candidates_that_sum_to_given_target()
            {
                var finder = new FactorFinder
                {
                    Candidates = new[]
                    {
                        1721, 979, 366, 299, 675, 1456
                    }
                };

                var result = finder.FindTwoCandidatesThatSumTo(2020).ToList();

                Assert.Contains(1721, result);
                Assert.Contains(299, result);
            }