class SolutionTest(unittest.TestCase): def setUp(self): self.sol = Solution() def test_1(self): l = [1, 2, 3] self.sol.nextPermutation(l) self.assertEqual(l, [1, 3, 2]) def test_2(self): l = [1, 2, 3, 2, 1] self.sol.nextPermutation(l) self.assertEqual(l, [1, 3, 1, 2, 2]) def test_3(self): l = [3, 2, 1, 1, 1] self.sol.nextPermutation(l) self.assertEqual(l, [1, 1, 1, 2, 3])