import unittest
from algo import gauss_method

class TestGaussMethod(unittest.TestCase):
    def test_2x2_unique_solution(self):
        """Простейшая 2x2 система с уникальным решением"""
        coef = [[1, 1],
                [2, 3]]
        free_mem = [5, 11]
        result = gauss_method(coef, free_mem)
        expected = [4.0, 1.0]
        for r, e in zip(result, expected):
            self.assertAlmostEqual(r, e, places=7)

    def test_2x2_another(self):
        """Ещё одна 2x2 система"""
        coef = [[2, 1],
                [4, 3]]
        free_mem = [5, 11]
        result = gauss_method(coef, free_mem)
        expected = [2.0, 1.0]
        for r, e in zip(result, expected):
            self.assertAlmostEqual(r, e, places=7)

    def test_3x3_unique_solution(self):
        """3x3 система с уникальным решением"""
        coef = [[1, 1, 1],
                [2, 3, 1],
                [1, 2, 3]]
        free_mem = [6, 11, 14]
        result = gauss_method(coef, free_mem)
        expected = [1.0, 2.0, 3.0]
        for r, e in zip(result, expected):
            self.assertAlmostEqual(r, e, places=7)

    def test_degenerate_system(self):
        """Вырожденная система должна выбросить исключение"""
        coef = [[1, 1],
                [2, 2]]
        free_mem = [2, 4]
        with self.assertRaises(ValueError):
            gauss_method(coef, free_mem)

if __name__ == "__main__":
    unittest.main()