Intersection in Python

Questions 1 to 5 of 6

1. 1. Lists C and D are built separately with build(1, 2) each. Both hold 1 -> 2, so their values match, but no node is shared. What do length_difference(c, d) and two_pointers(c, d) return?

   The node holding 1 from C, because the values matchThe node holding 2 from D, because 2 is the last value in both listsBoth raise an AttributeErrorBoth return None
2. 2. Which statements about the two methods in this lesson are true? Pick all that apply.

   Pick every answer that is true.

   length_difference makes three passes: it counts both lists, moves the longer head forward, then walks both togetherlength_difference can skip the counting step and still find the shared nodetwo_pointers needs the length of each list before it startstwo_pointers walks at most the total length of both lists plus one step, in one passBoth methods return None when the two lists share no node
3. 3. Using build, join, length_difference and two_pointers from this lesson, what does this code print? ``python shared = build(9, 3) a = join(build(1), shared) b = join(build(2, 4, 5), shared) print("first", length_difference(a, b).val, "second", two_pointers(a, b).val) ``

   first 9 second 9first 1 second 2first 3 second 3first 9 second None
4. 4. True or false, with a reason: two nodes that both hold the value 8, one in list A and one in list B, count as a shared node because their values match.

   True, because the methods compare the val attributes of the two nodesFalse, because the methods compare node objects with is, so two different nodes holding 8 are not sharedTrue, because Python's == on two nodes compares their values
5. 5. Which expression asks whether two references a and b point at the same node object?

   a.next is b.nexta is ba.val == b.vala.val == b.val and a.next == b.next