def add2(head1,head2):
# get each lenght and makup 0 nodes for the shorter one
l1 = ll.get_length(head1)
l2 = ll.get_length(head2)
#print "%d,%d" % (l1,l2)
if l1>=l2:
while l1 > l2:
zero = ll.ListNode(0)
zero.next = head2
head2 = zero
l2 += 1
else:
while l1 < l2:
zero = ll.ListNode(0)
zero.next = head1
head1 = zero
l1 += 1
#print "%d,%d" % (l1,l2)
ll.print_list(head1)
ll.print_list(head2)
res,flag = rec(head1,head2,l1-1)
if flag == 1:
return res+10**l1
else:
return res
def return_kth(head, k):
size = ll.get_length(head)
if not head or k > size:
print "invalid input"
return 0
# far = size-k+1
start = head
end = head
for i in range(k):
end = end.next
while end:
start = start.next
end = end.next
return start.val
def isPalidrome(head):
if not head or not head.next:
return True
size = ll.get_length(head)
return rec(head,size-1)