def test_keys_with_prefix_two_found(self):
t = TST()
t.insert("one", 1)
t.insert("two", 2)
t.delete("one")
t.insert("three", 3)
self.assertEqual(sorted(t.keys_with_prefix("t")), ["three", "two"])
def test_delete_after_inserting_again(self):
t = TST()
t.insert("boo", 0.5)
t.insert("neg", 1)
self.assertEqual(t.delete("neg"), 1)
t.insert("neg", 1)
self.assertEqual(t.delete("neg"), 1)
self.assertFalse(t.is_empty())
self.assertEqual(t.count(), 1)
def test_delete_same_key_twice(self):
t = TST()
t.insert("one", 1)
t.insert("two", 2)
t.insert("three", 3)
self.assertEqual(t.delete("three"), 3)
self.assertIsNone(t.delete("three"))
self.assertFalse(t.is_empty())
self.assertEqual(t.count(), 2)
self.assertTrue(t.contains("one"))
self.assertTrue(t.contains("two"))
self.assertEqual(t.search("one"), 1)
self.assertEqual(t.search("two"), 2)
def test_delete_the_only_key(self):
t = TST()
t.insert("seven", 7)
self.assertEqual(t.delete("seven"), 7)
self.assertTrue(t.is_empty())
self.assertEqual(t.count(), 0)
self.assertFalse(t.contains("seven"))
self.assertIsNone(t.search("seven"))
def test_delete_inexistent_key(self):
t = TST()
t.insert("first", "1st")
self.assertIsNone(t.delete("second"))
self.assertFalse(t.is_empty())
self.assertEqual(t.count(), 1)
self.assertTrue(t.contains("first"))
self.assertEqual(t.search("first"), "1st")
def test_delete_the_two_keys(self):
t = TST()
t.insert("one", 1)
t.insert("two", 2)
self.assertEqual(t.delete("one"), 1)
self.assertFalse(t.is_empty())
self.assertEqual(t.count(), 1)
self.assertFalse(t.contains("one"))
self.assertTrue(t.contains("two"))
self.assertIsNone(t.search("one"))
self.assertEqual(t.search("two"), 2)
self.assertEqual(t.delete("two"), 2)
self.assertTrue(t.is_empty())
self.assertEqual(t.count(), 0)
self.assertFalse(t.contains("one"))
self.assertFalse(t.contains("two"))
self.assertIsNone(t.search("one"))
self.assertIsNone(t.search("two"))
def test_delete_all_random_keys(self):
t = TST()
n = random.randint(3, 2000)
random_pairs = {}
for _ in range(n):
key = TestTST.gen_rand_str(random.randint(1, 11))
random_pairs[key] = key
t.insert(key, key)
for k, v in random_pairs.items():
self.assertEqual(t.delete(k), v)
self.assertIsNone(t.search(k))
self.assertFalse(t.contains(k))
self.assertTrue(t.is_empty())
self.assertEqual(t.count(), 0)
def test_delete_empty_tst(self):
t = TST()
self.assertIsNone(t.delete("war"))
