In `@datastructures/linked_lists/linked_list_utils.py`:
- Around line 44-50: The cycle-detection block uses slow_pointer, fast_pointer
and an optional func but when a cycle is found and func is provided the function
calls func(...) then falls through to return False, contradicting the docstring;
update the code in that branch so after calling func(slow_pointer, fast_pointer)
the function returns True (i.e., ensure both the func and non-func paths return
True when slow_pointer is fast_pointer) so the function consistently reports a
detected cycle.
- Around line 71-77: The cycle-detection loop mixes identity and equality
comparisons: the initial check uses "is" (slow_pointer is fast_pointer) but the
loop uses "!=" which invokes Node.__eq__ (compares keys) and can mis-detect
cycles when distinct nodes have equal keys; update the loop condition to use
identity ("is not") so both comparisons use identity semantics (referencing
slow_pointer and fast_pointer in the function containing the loop) to correctly
count the cycle length.
- Line 132: Change the node comparison in the loop to use identity comparison:
in the while loop that currently checks "while current.next != fixed_pointer"
(variables current and fixed_pointer), replace the inequality operator with an
identity check so it reads as "while current.next is not fixed_pointer"; this
ensures consistent node identity comparison with other functions that use "is" /
"is not".
- Line 39: The tuple unpacking "fast_pointer, slow_pointer = head" is invalid
because head is a single Node; replace it by assigning both pointers to the head
node (set fast_pointer and slow_pointer to head) so both start at the list head;
update the initialization in linked_list_utils.py where fast_pointer,
slow_pointer and head are referenced to use individual assignments (e.g., set
fast_pointer = head and slow_pointer = head) so subsequent logic in functions
using fast_pointer and slow_pointer works correctly.
- Around line 99-105: Replace equality checks with identity checks in the
cycle-detection logic: where the code compares slow_pointer and fast_pointer
(currently using ==) and where it compares current and slow_pointer (currently
using !=), use "is" and "is not" respectively so comparisons use object identity
rather than Node.__eq__ (which compares keys); update the comparisons in the
function containing slow_pointer, fast_pointer, current and head to use "is" /
"is not" so distinct nodes with equal keys are not treated as the same node.