def test1(self):
expect = [
[1,2,3],[1,3,2],
[2,1,3],[2,3,1],
[3,1,2],[3,2,1]
]
actual = Solution.permute("", [1,2,3])
self.assertEqual(expect, actual)
def test2(self):
expect = [
[1,2],[2,1]
]
actual = Solution.permute("", [1,2])
self.assertEqual(expect, actual)
