def test_merge_list_link2_head():
ll1 = LinkedList()
ll2 = LinkedList()
ll1.insert("a", "b", "c", "d", "e", "f")
actual = str(merge_list(ll1, ll2))
expected = "f : e : d : c : b : a : None"
assert actual == expected
def test_LinkedList_str():
ll = LinkedList()
ll.insert("a")
ll.insert("b")
actual = str(ll)
expected = "{ b } -> { a } -> NULL"
assert actual == expected
def test_merge_list_link1_head():
ll1 = LinkedList()
ll2 = LinkedList()
ll2.insert("A", "B", "C")
actual = str(merge_list(ll1, ll2))
expected = "C : B : A : None"
assert actual == expected
def test_filter():
nums = LinkedList()
for i in range(1, 21):
nums.insert(i)
odds = [num for num in nums if num % 2]
assert odds == [19, 17, 15, 13, 11, 9, 7, 5, 3, 1]
def test_next():
foods = LinkedList()
foods.insert("apple", "banana", "cucumber")
iterator = iter(foods)
assert next(iterator) == "cucumber"
assert next(iterator) == "banana"
assert next(iterator) == "apple"
def test_stop_iteration():
foods = LinkedList()
foods.insert("apple", "banana", "cucumber")
iterator = iter(foods)
with pytest.raises(StopIteration):
while True:
food = next(iterator)
def partition(ll, value):
# make a new linked list with a tail to hold high values and head to hold the small values
# O(n) time but O(n) for space for new linked list
output_ll = LinkedList()
output_ll.tail = output_ll.head
current = ll.head
while current:
if current.value < value:
if not output_ll.head:
output_ll.head = Node(current.value)
output_ll.tail = output_ll.head
else:
new_node = Node(current.value)
new_node.next = output_ll.head
output_ll.head = new_node
else:
#add to the tail
if not output_ll.tail:
output_ll.tail = Node(current.value)
output_ll.head = output_ll.tail
else:
new_node = Node(current.value)
output_ll.tail.next = new_node
output_ll.tail = new_node
current = current.next
return output_ll
def test_merge_lists_same_length():
ll1 = LinkedList()
ll2 = LinkedList()
ll1.insert("a", "b", "c")
ll2.insert("A", "B", "C")
actual = str(merge_list(ll1, ll2))
expected = 'c : C : b : B : a : A : None'
assert actual == expected
def test_merge_list_link2_long():
ll1 = LinkedList()
ll2 = LinkedList()
ll1.insert("a", "b", "c")
ll2.insert("A", "B", "C", "D", "E", "F")
actual = str(merge_list(ll1, ll2))
expected = "c : F : b : E : a : D : C : B : A : None"
assert actual == expected
def test_merge_list_link1_long():
ll1 = LinkedList()
ll2 = LinkedList()
ll1.insert("a", "b", "c", "d", "e", "f")
ll2.insert("A", "B", "C")
actual = str(merge_list(ll1, ll2))
expected = "f : C : e : B : d : A : c : b : a : None"
assert actual == expected
def test_equals():
lla = LinkedList()
lla.insert("apple", "banana", "cucumber")
llb = LinkedList()
llb.insert("apple", "banana", "cucumber")
assert len(lla) == len(llb)
assert str(lla) == str(llb)
def sum_lists2(ll_1, ll_2):
if not ll_1.head or not ll_2.head:
return "ll does not have head"
ll = LinkedList()
current_1 = ll_1.head
current_2 = ll_2.head
carry_over = 0
def get_new_value(sum, carry_over):
if sum > 9:
new_value = sum - 10
carry_over = 1
else:
new_value = sum
carry_over = 0
return new_value, carry_over
def add_to_tail(new_value):
ll.tail.next = Node(new_value)
ll.tail = ll.tail.next
while current_1 and current_2:
sum = current_1.value + current_2.value + carry_over
new_value, carry_over = get_new_value(sum, carry_over)
if not ll.head:
ll.head = Node(new_value)
ll.tail = ll.head
else:
add_to_tail(new_value)
current_1 = current_1.next
current_2 = current_2.next
if current_1:
remaining = current_1
else:
remaining = current_2
while remaining:
sum = remaining.value + carry_over
new_value, carry_over = get_new_value(sum, carry_over)
add_to_tail(new_value)
remaining = remaining.next
if carry_over:
ll.tail.next = Node(carry_over)
ll.tail = ll.tail.next
return ll
def test_LinkedList_includes_false():
ll = LinkedList()
ll.insert("a")
ll.insert("b")
ll.insert("c")
actual = ll.includes("d")
expected = False
assert actual == expected
def test_LinkedList_includes_true():
ll = LinkedList()
ll.insert("a")
ll.insert("b")
ll.insert("c")
actual = ll.includes("c")
expected = True
assert actual == expected
def test_LinkedList_append_empty_list():
ll = LinkedList()
ll.insert("1", "3", "2")
ll.append("5")
actual = str(ll)
expected = "{2} -> {3} -> {1} -> {5} -> NULL"
assert actual == expected
def test_LinkedList_insert_after_multiple_arg_single_link():
ll = LinkedList()
ll.insert("apples")
ll.insert_after("apples", "1", "2", "3")
actual = str(ll)
expected = "{apples} -> {3} -> {2} -> {1} -> NULL"
assert actual == expected
def test_LinkedList_insert_before_present_value():
ll = LinkedList()
ll.insert("oranges", "bananas", "coconut")
ll.insert_before("oranges", "kiwi")
actual = str(ll)
expected = "{coconut} -> {bananas} -> {kiwi} -> {oranges} -> NULL"
assert actual == expected
def test_LinkedList_insert_after_multiple_arg_large_link():
ll = LinkedList()
ll.insert("apples", "kiwi", "coconut", "pineapple")
ll.insert_after("kiwi", "1", "2", "3")
actual = str(ll)
expected = "{pineapple} -> {coconut} -> {kiwi} -> {3} -> {2} -> {1} -> {apples} -> NULL"
assert actual == expected
def test_LinkedList_insert_after_single_list():
ll = LinkedList()
ll.insert("apples")
ll.insert_after("apples", "1")
actual = str(ll)
expected = "{apples} -> {1} -> NULL"
assert actual == expected
def test_LinkedList_insert_after_single_new_value():
ll = LinkedList()
ll.insert("oranges", "kiwi", "bananas")
ll.insert_after("kiwi", "1")
actual = str(ll)
expected = "{bananas} -> {kiwi} -> {1} -> {oranges} -> NULL"
assert actual == expected
def test_LinkedList_insert_before_multiple_arg_long_head():
ll = LinkedList()
ll.insert("oranges", "kiwi", "bananas", "coconut")
ll.insert_before("kiwi", "1", "2", "3")
actual = str(ll)
expected = "{coconut} -> {bananas} -> {3} -> {2} -> {1} -> {kiwi} -> {oranges} -> NULL"
assert actual == expected
def test_LinkedList_insert_before_multiple_arg_just_head():
ll = LinkedList()
ll.insert("oranges")
ll.insert_before("oranges", "1", "2", "3")
actual = str(ll)
expected = "{3} -> {2} -> {1} -> {oranges} -> NULL"
assert actual == expected
def sum_lists(ll_1, ll_2):
if not ll_1.head or not ll_2.head:
return "ll does not have head"
ll = LinkedList()
current_1 = ll_1.head
current_2 = ll_2.head
carry_over = 0
while current_1 and current_2:
sum = current_1.value + current_2.value + carry_over
if sum > 9:
new_value = sum - 10
carry_over = 1
else:
new_value = sum
carry_over = 0
if not ll.head:
ll.head = Node(new_value)
ll.tail = ll.head
else:
ll.tail.next = Node(new_value)
ll.tail = ll.tail.next
current_1 = current_1.next
current_2 = current_2.next
while current_1:
sum = current_1.value + carry_over
if sum > 9:
new_value = sum - 10
carry_over = 1
else:
new_value = sum
carry_over = 0
ll.tail.next = Node(new_value)
ll.tail = ll.tail.next
current_1 = current_1.next
while current_2:
sum = current_2.value + carry_over
if sum > 9:
new_value = sum - 10
carry_over = 1
else:
new_value = sum
carry_over = 0
ll.tail.next = Node(new_value)
ll.tail = ll.tail.next
current_2 = current_2.next
if carry_over:
ll.tail.next = Node(carry_over)
ll.tail = ll.tail.next
return ll
def test_LinkedList_append_empty_list():
ll = LinkedList()
ll.append("5")
actual = str(ll)
expected = "{5} -> NULL"
assert actual == expected
def test_LinkedList_instantiation():
ll = LinkedList()
actual = ll.head
expected = None
assert actual == expected
def ll():
ll = LinkedList()
ll.insert("apples")
return ll
def test_kth_value_one():
ll = LinkedList()
ll.insert("1")
actual = ll.find_k_node_value2(0)
expected = '1'
assert actual == expected
def test_kth_value_mid_length():
ll = LinkedList()
ll.insert("1", "2", "3", "4", "5")
actual = ll.find_k_node_value2(2)
expected = '3'
assert actual == expected
def test_kth_value_negativeKay():
ll = LinkedList()
ll.insert("1", "2", "3")
actual = ll.find_k_node_value2(-15)
expected = "Exception"
assert actual == expected
def test_kth_value_empty_list():
ll = LinkedList()
actual = ll.find_k_node_value2(3)
expected = "Exception"
assert actual == expected
