def delete_duplicates(head):
seen_values = {}
my_node = head
prev = None
while my_node != None:
try:
x = seen_values[my_node.value] # If we don't get a key error here, we've seen the val before, so remove it.
prev.Next = my_node.Next
my_node = my_node.Next
except KeyError:
seen_values[my_node.value] = True
prev = my_node
my_node = my_node.Next
return head
if __name__ == "__main__":
vals = [1,2,3,4,3,5,6,1,7,8,9,3,10,2,11]
head = node()
my_node = head
for each in vals:
my_node.value = each
if each != vals[-1]:
my_node.Next = node()
my_node = my_node.Next
print("Linked list before deletions:")
print(traverse(head, False))
head = delete_duplicates(head)
print("Linked list after deletions:")
print(traverse(head, False))
import linked_lists
import random
def reverse(head, info=True):
if(info):
print("Linked list reversal")
print("Time complexity: O(n)")
print("Space complexity: O(1)")
try:
assert(isinstance(head, linked_lists.node))
except AssertionError:
return False
prev = None
while(head != None):
following = head.Next
head.Next = prev
prev = head
head = following
return prev
if __name__ == '__main__':
myList = linked_lists.set_up(random.randint(1,20))
repl = True
while(repl != "q"):
print linked_lists.traverse(myList)
myList = reverse(myList)
repl = raw_input("Press any key to continue, or \"q\" to quit.")
if a_head.value > b_head.value:
current.value = b_head.value
b_head = b_head.Next
else: # a_head.value <= b_head.value
current.value = a_head.value
a_head = a_head.Next
new_node = linked_lists.node()
current.Next = new_node
current = new_node
# One of the lists was empty, so shallow-copy the rest of the other
non_empty = a_head or b_head
if non_empty:
current.value = non_empty.value # resolve dangling value
current.Next = non_empty.Next # append and finish
else: # this happens only when both were passed in as None
head = None
return head
if __name__ == '__main__':
len_ll_a = random.randint(1,20)
ll_a = linked_lists.set_up(len_ll_a)
len_ll_b = random.randint(1,20)
ll_b = linked_lists.set_up(len_ll_b)
print "Length of List A: " + str(len_ll_a)
print "List A: " + str(linked_lists.traverse(ll_a, False))
print "Length of List B: " + str(len_ll_b)
print "List B: " + str(linked_lists.traverse(ll_b, False))
print "AB (merge of A and B): " + str(linked_lists.traverse(merge_shallow(ll_a, ll_b, False), False))