feat(trees): longest common suffix queries

[BrianLusina]

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• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Documentation change?

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• I have read CONTRIBUTING.md.
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Summary by CodeRabbit

• New Features

  • Introduced Suffix Tree data structure for efficient suffix-based pattern matching
  • Added longest common suffix queries capability to match query strings against a word container

• Documentation

  • Added documentation explaining suffix-based word matching with problem constraints and examples

• Tests

  • Implemented comprehensive test coverage for suffix matching functionality with multiple test scenarios

_{✏️ Tip: You can customize this high-level summary in your review settings.}

[coderabbitai]

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Review failed

The pull request is closed.

Walkthrough

Introduces a new Suffix Tree data structure that stores reversed words in a Trie and tracks best word information per node. Implements a longest common suffix queries function leveraging this structure. Adds comprehensive documentation and test coverage with nine test cases.

Changes

Cohort / File(s)	Summary
Documentation DIRECTORY.md, pystrings/longest_common_suffix_queries/README.md	DIRECTORY.md updated with entries for Suffix Tree and Longest Common Suffix Queries problem. README.md added documenting the problem statement, selection rules, and constraints.
Suffix Tree Core Types datastructures/trees/trie/suffix/types.py	Introduces WordInfo type alias (Tuple[int, int]) and INF_WORD_INFO constant for tracking best candidate information.
Suffix Tree Node datastructures/trees/trie/suffix/suffix_tree_node.py	New SuffixTreeNode class extending TrieNode with best_index and best_info tracking attributes and children defaultdict.
Suffix Tree Implementation datastructures/trees/trie/suffix/suffix_tree.py	New SuffixTree class storing reversed words in a Trie, with insert() to add words and search_best_index() to find best matching suffix. Includes _update_best_info() for comparing and propagating best word candidates.
Suffix Package Initialization datastructures/trees/trie/suffix/__init__.py	Package initializer re-exporting SuffixTree and SuffixTreeNode.
Trie Package Exports datastructures/trees/trie/__init__.py	Added imports and all exports for SuffixTreeNode and SuffixTree.
Longest Common Suffix Queries pystrings/longest_common_suffix_queries/__init__.py	New public function longest_common_suffix_queries() that constructs a SuffixTree from a word container, inserts words with indices, and searches for best matching suffixes for query words.
Longest Common Suffix Queries Tests pystrings/longest_common_suffix_queries/test_longest_common_suffix_queries.py	New test module with LongestCommonSuffixQueriesTestCase containing nine test methods covering various suffix matching scenarios.
Test Documentation datastructures/trees/binary/test_utils.py	Added detailed docstring to test_1 in LowestCommonAncestorTestCase describing the binary tree structure and expected LCA outcome.

Sequence Diagram(s)

sequenceDiagram
    participant Client
    participant LCS as longest_common_suffix_queries()
    participant ST as SuffixTree
    participant STN as SuffixTreeNode
    participant Trie as Trie (reversed paths)

    Client->>LCS: words_container, words_query
    activate LCS
    
    LCS->>ST: create()
    activate ST
    
    loop for each word in words_container
        LCS->>ST: insert(word, index)
        activate ST
        ST->>ST: reverse word
        ST->>Trie: traverse/insert reversed chars
        activate Trie
        Trie->>STN: update best_info at each node
        activate STN
        STN->>STN: compare & update via _update_best_info()
        deactivate STN
        deactivate Trie
        deactivate ST
    end
    
    deactivate ST
    
    loop for each query_word in words_query
        LCS->>ST: search_best_index(query_word)
        activate ST
        ST->>ST: reverse query_word
        ST->>Trie: traverse existing children
        activate Trie
        Trie->>STN: collect best_info from deepest node
        deactivate Trie
        ST-->>LCS: return original_index from best_info
        deactivate ST
    end
    
    LCS-->>Client: List[int] of best indices
    deactivate LCS

Loading

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

• Key areas requiring attention:
  • suffix_tree.py: Review the _update_best_info() tie-breaking logic (length first, then index) and ensure best_info propagation correctly accumulates along reversed word paths
  • longest_common_suffix_queries/__init__.py: Verify the algorithm correctly maps query results back to original indices
  • Test coverage: Nine test cases provide good scenarios, but verify they cover edge cases like empty containers, duplicate words, and partial matches
  • SuffixTreeNode inheritance and children defaultdict behavior integration with Trie parent class

Suggested labels

Documentation

Poem

🐰 A suffix tree stands, reversed and tall,
Through prefixes of backwards strings we crawl,
With best_info whispers at every node,
Common suffixes found along the code,
Nine tests ensure our queries don't fall!

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch feat/longest-common-suffix-queries

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📜 Recent review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 5ea5053 and 76f5797.

⛔ Files ignored due to path filters (5)

• pystrings/longest_common_suffix_queries/images/examples/longest_common_suffix_queries_1.png is excluded by !**/*.png
• pystrings/longest_common_suffix_queries/images/examples/longest_common_suffix_queries_2.png is excluded by !**/*.png
• pystrings/longest_common_suffix_queries/images/examples/longest_common_suffix_queries_3.png is excluded by !**/*.png
• pystrings/longest_common_suffix_queries/images/examples/longest_common_suffix_queries_4.png is excluded by !**/*.png
• pystrings/longest_common_suffix_queries/images/examples/longest_common_suffix_queries_5.png is excluded by !**/*.png

📒 Files selected for processing (10)

• DIRECTORY.md (2 hunks)
• datastructures/trees/binary/test_utils.py (1 hunks)
• datastructures/trees/trie/__init__.py (1 hunks)
• datastructures/trees/trie/suffix/__init__.py (1 hunks)
• datastructures/trees/trie/suffix/suffix_tree.py (1 hunks)
• datastructures/trees/trie/suffix/suffix_tree_node.py (1 hunks)
• datastructures/trees/trie/suffix/types.py (1 hunks)
• pystrings/longest_common_suffix_queries/README.md (1 hunks)
• pystrings/longest_common_suffix_queries/__init__.py (1 hunks)
• pystrings/longest_common_suffix_queries/test_longest_common_suffix_queries.py (1 hunks)

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