def test_big_diff1(self): self.assertEqual(big_diff([10, 3, 5, 6]), 7)
def test_big_diff5(self): self.assertEqual(big_diff([1, 1, 1, 1, 1]), 0)
def test_big_diff3(self): self.assertEqual(big_diff([-20, -10, -7, -2]), 18)
def test_big_diff4(self): self.assertEqual(big_diff([12, -4, 5, 9]), 16)
def test_big_diff2(self): self.assertEqual(big_diff([7, 2, 10, 9]), 8)