feat(algorithms, two-pointers): valid palindrome with one character removal#148
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BrianLusina
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enhancement
Algorithm
📝 WalkthroughWalkthroughThe changes reorganize palindrome-related code from the Pystrings module to Two Pointers, introduce a new algorithm to validate palindromes with up to one character removal, update all import paths accordingly, and apply formatting updates to documentation files. Changes
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Actionable comments posted: 2
🤖 Fix all issues with AI agents
In @algorithms/two_pointers/palindrome/README.md:
- Around line 250-252: Typo fix: update the README description for
is_valid_palindrome_with_one_char_removal to read "left_pointer at the start and
right_pointer at the end of the string" (add the missing article "the"); locate
the sentence that mentions left_pointer and right_pointer and insert "the"
before "end of the string" so the phrase becomes "at the end of the string".
In @DIRECTORY.md:
- Around line 221-232: The markdown list under the "Palindrome" section has
inconsistent indentation causing MD007 (ul-indent) errors; fix by aligning the
nesting to match the Two Pointers pattern: indent the "Palindrome" header 4
spaces, its direct children ("Largest Palindrome Product", "Longest Palindrome",
"Longest Palindromic Substring", "Palindrome Index", "Palindrome Pairs",
"Permutation Palindrome", "Test Palindrome", etc.) 6 spaces, and any test
sub-items (e.g., "Test Largest Palindrome Product", "Test Permutation
Palindrome", "Test Palindrome Index", "Test Palindrome Pairs") 8 spaces so the
list matches the surrounding sections and passes markdownlint-cli2.
🧹 Nitpick comments (2)
tests/pystrings/test_longest_palindrome.py (1)
18-24: Consider renaming test method to match the function being tested.The method
test_longest_palindrome_two(line 18) actually testslongest_palindrome_one(line 21). While this appears to be a pre-existing issue not introduced by this PR, consider renaming for clarity.Suggested rename
- def test_longest_palindrome_two(self): + def test_longest_palindrome_one_single_char(self): """Should return 1 for s = a""" s = "a" actual = longest_palindrome_one(s)algorithms/two_pointers/palindrome/test_palindrome.py (1)
144-160: Good test coverage. Consider adding edge case tests.The test cases cover a good variety of scenarios. Optionally, consider adding edge cases for completeness:
Suggested additional test cases
IS_PALINDROME_WITH_ONE_CHAR_REMOVAL_TEST_CASES = [ + ("a", True), # Single character - always valid + ("ab", True), # Two different chars - remove one + ("aa", True), # Two same chars - already palindrome ("aba", True), ("abca", True), ("abc", False), ("abccbxa", True), ("madame", True), ("dead", True), ("tebbem", False), ("eeccccbebaeeabebccceea", False), ]
📜 Review details
Configuration used: defaults
Review profile: CHILL
Plan: Pro
⛔ Files ignored due to path filters (9)
algorithms/two_pointers/palindrome/images/solutions/is_valid_palindrome_with_one_char_removal_solution_1.pngis excluded by!**/*.pngalgorithms/two_pointers/palindrome/images/solutions/is_valid_palindrome_with_one_char_removal_solution_2.pngis excluded by!**/*.pngalgorithms/two_pointers/palindrome/images/solutions/is_valid_palindrome_with_one_char_removal_solution_3.pngis excluded by!**/*.pngalgorithms/two_pointers/palindrome/images/solutions/is_valid_palindrome_with_one_char_removal_solution_4.pngis excluded by!**/*.pngalgorithms/two_pointers/palindrome/images/solutions/is_valid_palindrome_with_one_char_removal_solution_5.pngis excluded by!**/*.pngalgorithms/two_pointers/palindrome/images/solutions/is_valid_palindrome_with_one_char_removal_solution_6.pngis excluded by!**/*.pngalgorithms/two_pointers/palindrome/images/solutions/is_valid_palindrome_with_one_char_removal_solution_7.pngis excluded by!**/*.pngalgorithms/two_pointers/palindrome/images/solutions/is_valid_palindrome_with_one_char_removal_solution_8.pngis excluded by!**/*.pngalgorithms/two_pointers/palindrome/images/solutions/is_valid_palindrome_with_one_char_removal_solution_9.pngis excluded by!**/*.png
📒 Files selected for processing (20)
DIRECTORY.mdalgorithms/backtracking/partition_string/__init__.pyalgorithms/greedy/jump_game/README.mdalgorithms/two_pointers/palindrome/README.mdalgorithms/two_pointers/palindrome/__init__.pyalgorithms/two_pointers/palindrome/largest_palindrome_product/README.mdalgorithms/two_pointers/palindrome/largest_palindrome_product/__init__.pyalgorithms/two_pointers/palindrome/largest_palindrome_product/test_largest_palindrome_product.pyalgorithms/two_pointers/palindrome/longest_palindrome.pyalgorithms/two_pointers/palindrome/longest_palindromic_substring.pyalgorithms/two_pointers/palindrome/palindrome_index.pyalgorithms/two_pointers/palindrome/palindrome_pairs.pyalgorithms/two_pointers/palindrome/permutation_palindrome/README.mdalgorithms/two_pointers/palindrome/permutation_palindrome/__init__.pyalgorithms/two_pointers/palindrome/permutation_palindrome/test_permutation_palindrome.pyalgorithms/two_pointers/palindrome/test_palindrome.pyalgorithms/two_pointers/palindrome/test_palindrome_index.pyalgorithms/two_pointers/palindrome/test_palindrome_pairs.pydatastructures/trees/binary/README.mdtests/pystrings/test_longest_palindrome.py
🧰 Additional context used
🧬 Code graph analysis (3)
algorithms/backtracking/partition_string/__init__.py (1)
algorithms/two_pointers/palindrome/__init__.py (1)
is_palindrome(1-52)
tests/pystrings/test_longest_palindrome.py (1)
algorithms/two_pointers/palindrome/longest_palindrome.py (2)
longest_palindrome_one(19-53)longest_palindrome_two(56-96)
algorithms/two_pointers/palindrome/test_palindrome.py (1)
algorithms/two_pointers/palindrome/__init__.py (1)
is_valid_palindrome_with_one_char_removal(167-206)
🪛 markdownlint-cli2 (0.18.1)
DIRECTORY.md
221-221: Unordered list indentation
Expected: 2; Actual: 4
(MD007, ul-indent)
222-222: Unordered list indentation
Expected: 4; Actual: 6
(MD007, ul-indent)
223-223: Unordered list indentation
Expected: 6; Actual: 8
(MD007, ul-indent)
224-224: Unordered list indentation
Expected: 4; Actual: 6
(MD007, ul-indent)
225-225: Unordered list indentation
Expected: 4; Actual: 6
(MD007, ul-indent)
226-226: Unordered list indentation
Expected: 4; Actual: 6
(MD007, ul-indent)
227-227: Unordered list indentation
Expected: 4; Actual: 6
(MD007, ul-indent)
228-228: Unordered list indentation
Expected: 4; Actual: 6
(MD007, ul-indent)
229-229: Unordered list indentation
Expected: 6; Actual: 8
(MD007, ul-indent)
230-230: Unordered list indentation
Expected: 4; Actual: 6
(MD007, ul-indent)
231-231: Unordered list indentation
Expected: 4; Actual: 6
(MD007, ul-indent)
232-232: Unordered list indentation
Expected: 4; Actual: 6
(MD007, ul-indent)
🔇 Additional comments (8)
algorithms/greedy/jump_game/README.md (1)
70-87: Documentation formatting improvements approved.Wrapping variable names and code expressions in backticks enhances readability and clearly distinguishes code elements from explanatory text. These formatting enhancements support better documentation clarity.
datastructures/trees/binary/README.md (1)
39-44: Documentation formatting and clarity improvements approved.Adding inline code formatting around pointers and conditions (
ptr1,ptr2,ptr1.parent, etc.) and ensuring precise punctuation placement within code notation improves the documentation's clarity and technical accuracy.DIRECTORY.md (1)
221-232: Verify all referenced palindrome files exist in the repository.The reorganization introduces multiple new entries and test file references under
algorithms/two_pointers/palindrome/. Ensure that all paths listed are accurate and that corresponding files exist in the repository structure, particularly:
algorithms/two_pointers/palindrome/longest_palindrome.pyalgorithms/two_pointers/palindrome/longest_palindromic_substring.pyalgorithms/two_pointers/palindrome/palindrome_index.pyalgorithms/two_pointers/palindrome/palindrome_pairs.pyalgorithms/two_pointers/palindrome/test_palindrome.pytests/pystrings/test_longest_palindrome.py (1)
3-6: LGTM!Import path correctly updated to reflect the new module location under
algorithms.two_pointers.palindrome.algorithms/backtracking/partition_string/__init__.py (1)
2-2: LGTM!Import path correctly updated to reference
is_palindromefrom the newalgorithms.two_pointers.palindromemodule.algorithms/two_pointers/palindrome/__init__.py (1)
167-206: LGTM! Well-implemented two-pointer algorithm.The implementation correctly handles the Valid Palindrome II problem with O(n) time and O(1) space complexity. The nested
is_substring_palindromehelper appropriately capturessfrom the enclosing scope.One minor note: an empty string input (
"") will returnTruesince the loop condition fails immediately. This behavior seems acceptable given the problem constraints state1 <= s.length, but consider adding an explicit check or doctest if empty string handling is important.algorithms/two_pointers/palindrome/test_palindrome.py (1)
6-14: LGTM!Import paths correctly updated to reference the new module location, and the new
is_valid_palindrome_with_one_char_removalfunction is properly imported for testing.algorithms/two_pointers/palindrome/README.md (1)
261-270: All referenced image files exist. Verification confirms that all 9 solution images are present at the specified paths in the repository.
BrianLusina
deleted the
feat/algorithms-two-pointers-valid-palindrome-2
branch
1 participant
Describe your change:
Algorithm to check if a string is a valid palindrome if at most one character is removed
Checklist:
Fixes: #{$ISSUE_NO}.Summary by CodeRabbit
New Features
Documentation
Tests
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