def test_empty_matrix(self):
self.assertEqual(set(), saddle_points([]))
def test_no_saddle(self):
self.assertEqual(set(), saddle_points([[2, 1], [1, 2]]))
def test_mult_saddle(self):
inp = [[5, 3, 5, 4], [6, 4, 7, 3], [5, 1, 5, 3]]
ans = set([(0, 0), (0, 2), (2, 0), (2, 2)])
self.assertEqual(ans, saddle_points(inp))
def test_one_saddle(self):
inp = [[9, 8, 7], [5, 3, 2], [6, 6, 7]]
self.assertEqual(set([(1, 0)]), saddle_points(inp))
