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 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 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