def test_problem_2_3(self):
n1 = ll.Node(1, None)
n2 = ll.Node(2, n1)
n10 = ll.Node(10, n2)
n5 = ll.Node(5, n10)
string_representation = ''
head = n5
p_2_3.delete_middle(n10)
while head is not None:
string_representation += str(head.value)
head = head.next_node
self.assertEqual(string_representation, '521')
def test_problem_2_1_alternative(self):
n0 = ll.Node(9, None)
n1 = ll.Node(7, n0)
n2 = ll.Node(2, n1)
n3 = ll.Node(5, n2)
n4 = ll.Node(3, n3)
n5 = ll.Node(3, n4)
n6 = ll.Node(7, n5)
self.assertEqual('7,3,3,5,2,7,9,', ll.stringify_linked_list(n6))
p_2_1.remove_dups_alternative(n6)
self.assertEqual('7,3,5,2,9,', ll.stringify_linked_list(n6))
def test_problem_2_5(self):
"""
List1: 3 -> 2 -> 4 -> 9 -> NONE
List2: 1 -> 5 -> 9 -> NONE
9423
+ 951
-----
10374
"""
# first list
n14 = ll.Node(9, None)
n13 = ll.Node(4, n14)
n12 = ll.Node(2, n13)
n11 = ll.Node(3, n12)
# second list
n23 = ll.Node(9, None)
n22 = ll.Node(5, n23)
n21 = ll.Node(1, n22)
sum_head = p_2_5.sum_lists(n11, n21)
list_num = ""
while sum_head is not None:
list_num = str(
sum_head.value) + list_num # careful to reverse order!
sum_head = sum_head.next_node
self.assertEqual(list_num, '10374')
def test_problem_2_2(self):
n0 = ll.Node(9, None)
n1 = ll.Node(7, n0)
n2 = ll.Node(2, n1)
n3 = ll.Node(5, n2)
n4 = ll.Node(3, n3)
n5 = ll.Node(3, n4)
n6 = ll.Node(7, n5)
self.assertEqual(n2, p_2_2.return_kth_to_last(n6, 3))
self.assertEqual(n5, p_2_2.return_kth_to_last(n6, 6))
self.assertEqual(None, p_2_2.return_kth_to_last(n6, 0))
def test_problem_2_4(self):
n1 = ll.Node(1, None)
n2 = ll.Node(2, n1)
n10 = ll.Node(10, n2)
n5_1 = ll.Node(5, n10)
n8 = ll.Node(8, n5_1)
n5_0 = ll.Node(5, n8)
n3 = ll.Node(3, n5_0)
new_head = p_2_4.partition(n3, 5)
string_representation = ''
while new_head is not None:
string_representation += str(new_head.value)
new_head = new_head.next_node
self.assertEqual(string_representation, '12358510')
def test_problem_2_8(self):
# see problem_2_8_explanation.pdf
# example #1
node1_7 = ll.Node(7, None)
node1_6 = ll.Node(6, node1_7)
node1_5 = ll.Node(5, node1_6)
node1_4 = ll.Node(4, node1_5)
node1_3 = ll.Node(3, node1_4)
node1_2 = ll.Node(2, node1_3)
node1_1 = ll.Node(1, node1_2)
node1_0 = ll.Node(0, node1_1)
node1_7.next_node = node1_5
self.assertEqual(p_2_8.find_loop(node1_0), node1_5)
# example #2
node2_10 = ll.Node(7, None)
node2_9 = ll.Node(7, node2_10)
node2_8 = ll.Node(7, node2_9)
node2_7 = ll.Node(7, node2_8)
node2_6 = ll.Node(6, node2_7)
node2_5 = ll.Node(5, node2_6)
node2_4 = ll.Node(4, node2_5)
node2_3 = ll.Node(3, node2_4)
node2_2 = ll.Node(2, node2_3)
node2_1 = ll.Node(1, node2_2)
node2_0 = ll.Node(0, node2_1)
node2_10.next_node = node2_3
self.assertEqual(p_2_8.find_loop(node2_0), node2_3)
def test_problem_2_7(self):
# list 1
node1_7 = ll.Node(7, None)
node1_6 = ll.Node(6, node1_7)
node1_5 = ll.Node(5, node1_6)
node1_4 = ll.Node(4, node1_5)
node1_3 = ll.Node(3, node1_4)
node1_2 = ll.Node(2, node1_3)
node1_1 = ll.Node(1, node1_2)
node1_0 = ll.Node(0, node1_1)
# list 2
node2_5 = ll.Node(5, node1_6) # intersection point
node2_4 = ll.Node(4, node2_5)
node2_3 = ll.Node(3, node2_4)
node2_2 = ll.Node(2, node2_3)
self.assertEqual(node1_6, p_2_7.intersection(node2_2, node1_0))
def test_problem_2_6(self):
# list 1
node1_7 = ll.Node(0, None)
node1_6 = ll.Node(4, node1_7)
node1_5 = ll.Node(7, node1_6)
node1_4 = ll.Node(0, node1_5)
node1_3 = ll.Node(0, node1_4)
node1_2 = ll.Node(7, node1_3)
node1_1 = ll.Node(4, node1_2)
node1_0 = ll.Node(0, node1_1)
# list 2
node2_4 = ll.Node(3, None)
node2_3 = ll.Node(5, node2_4)
node2_2 = ll.Node(2, node2_3)
node2_1 = ll.Node(5, node2_2)
node2_0 = ll.Node(3, node2_1)
# list 3
node3_5 = ll.Node(1, None)
node3_4 = ll.Node(0, node3_5)
node3_3 = ll.Node(1, node3_4)
node3_2 = ll.Node(0, node3_3)
node3_1 = ll.Node(1, node3_2)
node3_0 = ll.Node(0, node3_1)
self.assertTrue(p_2_6.palindrome(node1_0))
self.assertTrue(p_2_6.palindrome(node2_0))
self.assertFalse(p_2_6.palindrome(node3_0))
def test_problem_2_7(self):
# list 1
node1_6 = ll.Node(1, None)
node1_5 = ll.Node(2, node1_6)
node1_4 = ll.Node(7, node1_5)
node1_3 = ll.Node(9, node1_4)
node1_2 = ll.Node(5, node1_3)
node1_1 = ll.Node(1, node1_2)
node1_0 = ll.Node(3, node1_1)
# list 2
node2_1 = ll.Node(6, node1_4) # intersection point
node2_0 = ll.Node(4, node2_1)
# list 3
node3_1 = ll.Node(6, None)
node3_0 = ll.Node(4, node3_1)
self.assertEqual(node1_4, p_2_7.intersection(node2_0, node1_0))
self.assertEqual(None, p_2_7.intersection(node1_0, node3_0))
self.assertEqual(None, p_2_7.intersection(None, None))