1796: Second Largest Digit in a String

[WazedKhan]

Summary by CodeRabbit

• New Features

  • Added a new LeetCode solution for identifying the second-largest digit within a string input.

• Tests

  • Implemented comprehensive test suite covering multiple cases and expected outcomes for the new functionality.

[coderabbitai]

Walkthrough

A new LeetCode solution is introduced to find the second-largest digit in a string, with a two-variable tracking approach. Test cases are added to validate the solution, and spacing is normalized in existing test tuples.

Changes

Cohort / File(s)	Change Summary
New LeetCode Solution LeetCode/easy/second_largest_digit_in_string_1796.py	Introduces Solution class with secondHighest(s: str) -> int method. Iterates through input string characters, maintains variables for largest and second-largest digits (initialized to -1), updates them when digits are encountered, and returns the second-largest digit (or -1 if unavailable).
Test Suite Updates tests/test_leetcode_easy.py	Normalizes spacing in existing test tuples. Adds new test function test_second_highest that imports Solution from the new module and runs assertions across multiple test cases with expected outputs.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~12 minutes

• Verify the digit extraction logic correctly identifies numeric characters
• Confirm the two-variable tracking accurately updates first and second maximums
• Validate test cases cover edge cases (no digits, single digit, multiple duplicates)

Poem

🐰 A digit hunt through string so long,
Tracking largest, oh so strong!
Second-best with quiet grace,
Finds its place, leaves nary a trace.
✨ Two variables dance and play,
Second-highest saves the day!

Pre-merge checks and finishing touches

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	You can run @coderabbitai generate docstrings to improve docstring coverage.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and specifically identifies the LeetCode problem (1796) and the main change being added (Second Largest Digit in a String solution).

✨ 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 1796-second-largest-digit-in-string

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[coderabbitai]

Actionable comments posted: 0

🧹 Nitpick comments (1)

LeetCode/easy/second_largest_digit_in_string_1796.py (1)

1-12: Algorithm is correct; consider elif for clarity.

The logic correctly tracks the two largest distinct digits. However, the second if at line 10 is effectively mutually exclusive with the first if at line 7 (since after first = d, the condition first > d > second becomes d > d > second, which is always False).

Consider this refactor for clarity:

         if char.isdigit():
             d = int(char)
             if d > first:
                 second = first
                 first = d
-            if first > d > second:
+            elif first > d > second:
                 second = d

This makes the mutual exclusivity explicit and improves readability.

📜 Review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 333142e and 62a86b7.

📒 Files selected for processing (2)

• LeetCode/easy/second_largest_digit_in_string_1796.py (1 hunks)
• tests/test_leetcode_easy.py (2 hunks)

🧰 Additional context used

🧬 Code graph analysis (1)

tests/test_leetcode_easy.py (2)

LeetCode/easy/second_largest_digit_in_string_1796.py (2)

• Solution (1-12)
• secondHighest (2-12)

LeetCode/easy/merge_sorted_array_88.py (1)

• Solution (6-33)

🔇 Additional comments (2)

tests/test_leetcode_easy.py (2)

8-27: LGTM: Spacing normalization improves consistency.

The spacing adjustments in the test tuples improve readability without changing functionality.

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94-116: Excellent test coverage for the second largest digit problem.

The test suite comprehensively covers:

• Normal cases with multiple unique digits
• Edge cases (no digits, single unique digit, all same digits)
• Boundary cases (all digits 0-9, scattered digits)
• Duplicate handling

The test cases align well with the implementation and should catch potential issues.