datastructures/trees/trie/suffix/suffix_tree_node.py (1)

7-21: Avoid redundant best_index state or ensure it’s consistently updated

The node now exposes both:

• best_index = -1, and
• best_info: WordInfo = INF_WORD_INFO (where the second element already encodes the index),

while the docstring talks about “the index of the best word”. In the current code, SuffixTree only uses best_info, so best_index stays at -1 and can be misleading if accessed.

To keep the API clear and avoid future divergence:

• Either remove best_index for now and rely solely on best_info[1], or
• Wire best_index into the update path (e.g., set it whenever best_info changes in insert) so it always mirrors best_info[1].

DIRECTORY.md (2)

229-241: Fix list indentation and spelling for Singly Linked List entries

• Lines 231 and 241 are indented two spaces deeper than their sibling bullets, which triggers markdownlint (MD007, ul-indent). Consider reducing indentation to match the other items under “Singly Linked List”.
• The visible label “Test Singly Linked Revese” (Line 241) has a typo; if you keep the filename test_singly_linked_revese.py for historical reasons, you can still fix the link text to “Reverse” while leaving the URL unchanged.

---

540-547: Align heap puzzle bullets with markdown list indentation rules

For the new “Min Cost To Connect Sticks” section:

• Line 546 (* Min Cost To Connect Sticks) is indented more than its sibling bullets under * Heap; markdownlint expects 2 leading spaces here.
• Line 547 (* [Test Min Cost Connect Sticks]) similarly has 2 extra spaces and should be aligned with other second‑level bullets.

Adjusting the indentation will keep the hierarchy consistent and clear both MD007 warnings.

datastructures/linked_lists/singly_linked_list/test_singly_linked_revese.py (2)

10-23: Good edge coverage; consider adding a right > len(list) failure test

The empty-list and left > right cases are well covered and align with the current reverse_between validation behavior.

Given the implementation also explicitly raises when right > len(self), it would be useful to add a test that asserts ValueError for that path as well (for example, a non-empty list with right one past the length) to lock in that contract.

---

24-71: Parameterized tests are solid; you can DRY shared cases and add minor refinements

These parameterized tests give good coverage of typical and non-trivial sublist reversals for both reverse_between and reverse_between_with_dummy, including full-list reversals and interior segments.

A few optional improvements:

• One test tuple in the case list is duplicated (the [103, 7, 10, -9, 105, 67, 31, 63], 1, 8, [...] case appears twice); you can drop the duplicate without losing coverage.
• The case lists for test_reverse_between and test_reverse_between_with_dummy are identical. Consider extracting them into a shared module-level constant (e.g., REVERSE_BETWEEN_CASES) and reusing in both decorators to keep them in sync.
• If you want to fully exercise the new validations, you could also add:
  • a case where left == right (no-op reversal), and
  • a case where right > len(list) that asserts ValueError for both implementations.

Also applies to: 73-120

datastructures/linked_lists/singly_linked_list/single_linked_list.py (1)

92-95: Stubbed methods should either be implemented or fail loudly

Several methods are present but unimplemented:

• insert_before_node (Lines 92-95)
• display_backward and display_forward (Lines 523-528)
• remove_tail (Lines 976-977)
• pairs_with_sum (Lines 1119-1120)

Right now they silently do nothing (or return None), which can make debugging difficult if they’re accidentally called.

Consider either:

• Implementing them, or
• Raising NotImplementedError with a short message so misuse is obvious.

For example:

 def insert_before_node(self, next_key: Any, data: T):
-
-        pass
+        raise NotImplementedError("insert_before_node is not implemented yet")

Same pattern can be applied to the others until you’re ready to add full implementations.

Also applies to: 523-528, 976-977, 1119-1120

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro