def main():
head1 = create_linked_list([4, 8, 15, 19])
head2 = create_linked_list([7, 9, 10, 16])
print("head1: " + print_linked_list(head1))
print("head2: " + print_linked_list(head2))
head1 = merge_sorted(head1, head2)
print("merged (head1): " + print_linked_list(head1))
def test(self):
s = Solution()
l1 = create_linked_list([9, 9])
l2 = create_linked_list([1])
result = print_linked_list(s.addTwoNumbers(l1, l2))
self.assertListEqual([0, 0, 1], result)
if lst1.data < lst2.data:
tail.next = lst1 # the FIRST tail.next node is where the actual merge begins
lst1 = lst1.next
else:
tail.next = lst2
lst2 = lst2.next
tail = tail.next
# append the remaining nodes of list 1 or list 2
tail.next = lst1 or lst2 # when one list becomes None, the 'or' returns the remaining nodes of the other
return dummy_head.next # dummy_head.next is the node appended with the FIRST tail.next statement
if __name__ == '__main__':
lst1 = ListNode(2)
lst2 = ListNode(3)
insert_after(lst1, ListNode(5))
insert_after(lst1.next, ListNode(7))
insert_after(lst2, ListNode(11))
print("List 1: ")
print_linked_list(lst1)
print("\nList 2: ")
print_linked_list(lst2)
res = merge_two_sorted_lists(lst1, lst2)
print("\nLists sorted and merged: ")
print_linked_list(res)
def test(self):
s = Solution()
l1 = create_linked_list([1, 2, 4])
l2 = create_linked_list([1, 3, 4])
self.assertListEqual([1, 1, 2, 3, 4, 4],
print_linked_list(s.mergeTwoLists(l1, l2)))
def test(self):
l1 = create_linked_list([1, 4, 5])
l2 = create_linked_list([1, 3, 5])
l3 = create_linked_list([2, 6])
s = Solution2().mergeKLists([l1, l2, l3])
self.assertListEqual([1, 1, 2, 3, 4, 5, 5, 6], print_linked_list(s))
move temp = 4 to the head of the sublist
2.next = 4.next = 5 (2 followed by 5), temp.next = head.next = 3 (4 followed by 3), head.next = temp = 4
=> 4, 3, 2, 5
Step 4: head = 1, iterator = 2, temp = iterator.next = 5
move temp = 5 to the head of the sublist...
=> 5, 4, 3, 2
The node that follows iterator is always the one to move to the head of the sublist
'''
sublist_iter = sublist_head.next
for _ in range(finish - start):
temp = sublist_iter.next
sublist_iter.next = temp.next
temp.next = sublist_head.next
sublist_head.next = temp
return dummy_head.next # dummy_head.next points to lst
if __name__ == '__main__':
lst = ListNode(11)
insert_after(lst, ListNode(3))
insert_after(lst.next, ListNode(5))
insert_after(lst.next.next, ListNode(7))
insert_after(lst.next.next.next, ListNode(2))
print("Original list: ")
print_linked_list(lst)
reverse_sublist(lst, 2, 4)
print("\nList after reversal: ")
print_linked_list(lst)
def test(self):
s = BetterSolution()
lst = create_linked_list([1, 2, 3, 4])
self.assertListEqual([2, 1, 4, 3], print_linked_list(s.swapPairs(lst)))