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1. Why does this function raise RecursionError on any non-empty list? ``

python
def length_stuck(node):
    if node is None:
        return 0
    return 1 + length_stuck(node)

``

It adds 1 on every call, so the total grows until it overflowsPython does not allow a function to call itself inside a return lineIt calls itself with node instead of node.next, so the input never gets smaller and the None case is never reachedIt reads node.value before the None check

2. What does this print? reverse_buggy below reverses the links correctly, but it returns head. It uses the from_list and show helpers from this lesson. ``

python
def reverse_buggy(head):
    if head is None or head.next is None:
        return head
    new_head = reverse_buggy(head.next)
    head.next.next = head
    head.next = None
    return head

print(show(reverse_buggy(from_list(1, 2, 3))))

``

3 -> 2 -> 11 -> 2 -> 3(empty)1

3. What does this print? It uses the from_list, show and reverse_in_groups helpers from this lesson. ``

python
print(show(reverse_in_groups(from_list(1, 2, 3, 4, 5, 6, 7), 3)))

``

1 -> 2 -> 3 -> 4 -> 5 -> 6 -> 73 -> 2 -> 1 -> 6 -> 5 -> 4 -> 73 -> 2 -> 1 -> 7 -> 6 -> 5 -> 43 -> 2 -> 1 -> 4 -> 5 -> 6 -> 7

4. True or false, and why: the loop version of length from the recursion lesson can walk a list of any length without a RecursionError.

False, because the loop still uses one call frame for each nodeTrue, because it makes no new calls and reuses the same two variables, n and cur, on every step

5. True or false, and why: reverse_in_groups reverses a short last block that has fewer than k nodes, because its loop only stops when the list is empty.

False, because the search for kth reaches None on a short block, and the loop breaks before that block is reversedTrue, because the loop keeps going until group_prev reaches the end of the list

Recursion depth and groups in Python