test sliding window funcs

[dchou1618]

User description

longest substr

---

PR Type

Enhancement, Tests

---

Description

• Implement sliding window algorithms for longest substring and maximum subarray

• Add lengthOfLongestSubstringTwoDistinct function with OrderedDict tracking

• Add maximumUniqueSubarray function for finding max sum of unique elements

• Comprehensive test suite with 30+ test cases covering edge cases and validation

---

Diagram Walkthrough

flowchart LR
  A["Sliding Window Algorithms"] --> B["lengthOfLongestSubstringTwoDistinct"]
  A --> C["maximumUniqueSubarray"]
  B --> D["OrderedDict tracking"]
  C --> E["Hash map with index tracking"]
  D --> F["Test Suite"]
  E --> F
  F --> G["30+ parametrized tests"]
  F --> H["Edge cases & validation"]

Loading

File Walkthrough

	Relevant files
Enhancement	longestUnique.py Sliding window algorithms for substring and subarray problems Algorithms/slidingWindow/longestUnique.py Implement lengthOfLongestSubstringTwoDistinct using OrderedDict to track at most 2 distinct characters Implement maximumUniqueSubarray to find maximum sum of subarray with all unique elements Define SlidingWindowParam Pydantic model for input validation with minimum length constraint Both functions use sliding window technique with efficient pointer management +35/-0
Tests	test_longest_substring.py Comprehensive test suite for sliding window algorithms      tests/test_longest_substring.py Add 7 parametrized basic correctness tests for lengthOfLongestSubstringTwoDistinct Add 7 parametrized basic correctness tests for maximumUniqueSubarray Add 8 regression and tricky case tests including eviction order and multiple duplicates Add 6 edge case tests covering all same characters, large values, and alternating patterns Add Pydantic validation tests for empty string rejection and type checking Add 8 invariant-style tests ensuring results respect bounds constraints +164/-0

---

[qodo-code-review]

PR Compliance Guide 🔍

Below is a summary of compliance checks for this PR:

Security Compliance
⚪	Algorithmic complexity Description: maximumUniqueSubarray performs sum(nums[start:(last_idx+1)]) inside the main loop, which can degrade to O(n^2) time on adversarial inputs with frequent duplicates, creating a realistic algorithmic-complexity (DoS) risk if nums is user-controlled and large. longestUnique.py [23-33] Referred Code def maximumUniqueSubarray(nums: List[int]) -> int: last_seen = dict() start, curr_sum, max_sum = 0, 0, 0 for end in range(len(nums)): if nums[end] in last_seen: last_idx = last_seen[nums[end]] if last_idx >= start: curr_sum -= sum(nums[start:(last_idx+1)]) start = last_idx + 1 curr_sum += nums[end] max_sum = max(max_sum, curr_sum)
Ticket Compliance
⚪	🎫 No ticket provided Create ticket/issue
Codebase Duplication Compliance
⚪	Codebase context is not defined Follow the guide to enable codebase context checks.
Custom Compliance
🟢	Generic: Comprehensive Audit Trails Objective: To create a detailed and reliable record of critical system actions for security analysis and compliance. Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Secure Error Handling Objective: To prevent the leakage of sensitive system information through error messages while providing sufficient detail for internal debugging. Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Secure Logging Practices Objective: To ensure logs are useful for debugging and auditing without exposing sensitive information like PII, PHI, or cardholder data. Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
🔴	Generic: Robust Error Handling and Edge Case Management Objective: Ensure comprehensive error handling that provides meaningful context and graceful degradation Status: Incorrect input type: lengthOfLongestSubstringTwoDistinct will raise runtime errors if called according to its signature (passing a SlidingWindowParam), because it performs string indexing and len() operations on the model instead of its s field. Referred Code def lengthOfLongestSubstringTwoDistinct(s: SlidingWindowParam) -> int: seen = OrderedDict() start = 0 longest = 0 for end in range(len(s)): if s[end] in seen: seen.move_to_end(s[end]) seen[s[end]] = end if len(seen) > 2: _, idx = seen.popitem(last=False) start = idx+1 longest = max(longest, end-start+1) return longest Learn more about managing compliance generic rules or creating your own custom rules
⚪	Generic: Meaningful Naming and Self-Documenting Code Objective: Ensure all identifiers clearly express their purpose and intent, making code self-documenting Status: Misleading type hint: The function lengthOfLongestSubstringTwoDistinct type-annotates s as SlidingWindowParam but uses it like a string, which is misleading and harms self-documentation. Referred Code def lengthOfLongestSubstringTwoDistinct(s: SlidingWindowParam) -> int: seen = OrderedDict() start = 0 longest = 0 for end in range(len(s)): if s[end] in seen: seen.move_to_end(s[end]) seen[s[end]] = end Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Security-First Input Validation and Data Handling Objective: Ensure all data inputs are validated, sanitized, and handled securely to prevent vulnerabilities Status: Missing nums validation: maximumUniqueSubarray accepts nums without validating type/contents (e.g., non-list inputs or non-integer elements), which may be acceptable for an algorithms module but is unverified from the diff alone. Referred Code def maximumUniqueSubarray(nums: List[int]) -> int: last_seen = dict() start, curr_sum, max_sum = 0, 0, 0 for end in range(len(nums)): if nums[end] in last_seen: last_idx = last_seen[nums[end]] if last_idx >= start: curr_sum -= sum(nums[start:(last_idx+1)]) start = last_idx + 1 curr_sum += nums[end] max_sum = max(max_sum, curr_sum) last_seen[nums[end]] = end return max_sum Learn more about managing compliance generic rules or creating your own custom rules

Compliance status legend

🟢 - Fully Compliant
🟡 - Partial Compliant
🔴 - Not Compliant
⚪ - Requires Further Human Verification
🏷️ - Compliance label

[qodo-code-review]

PR Code Suggestions ✨

Explore these optional code suggestions:

Category	Suggestion	Impact
General	Use string parameter type Change the signature of lengthOfLongestSubstringTwoDistinct to accept a str parameter instead of SlidingWindowParam to match its usage in the tests. Algorithms/slidingWindow/longestUnique.py [9] -def lengthOfLongestSubstringTwoDistinct(s: SlidingWindowParam) -> int: +def lengthOfLongestSubstringTwoDistinct(s: str) -> int: Apply / Chat Suggestion importance[1-10]: 9 __ Why: The suggestion correctly identifies a critical inconsistency between the function's type hint (SlidingWindowParam) and its actual usage with a str in tests, proposing a fix that makes the code correct and logical.	High
	Optimize window sum eviction In maximumUniqueSubarray, replace the inefficient sum(nums[start:(last_idx+1)]) with a loop to improve performance from O(N^2) to O(N). Algorithms/slidingWindow/longestUnique.py [30] -curr_sum -= sum(nums[start:(last_idx+1)]) +for i in range(start, last_idx+1): + curr_sum -= nums[i] +start = last_idx + 1 Apply / Chat Suggestion importance[1-10]: 8 __ Why: The suggestion correctly identifies a significant performance bottleneck (sum on a slice) that results in O(N^2) complexity and proposes a fix that improves it to O(N).	Medium
Possible issue	Avoid duplicate test names Rename the test function test_basic_cases at line 37 to a unique name to prevent it from overwriting the other test with the same name. tests/test_longest_substring.py [37] -def test_basic_cases(nums, expected): +def test_maximum_unique_subarray_basic_cases(nums, expected): Apply / Chat Suggestion importance[1-10]: 7 __ Why: The suggestion correctly points out that two test functions have the same name, which would cause pytest to run only the second one, leaving the first untested.	Medium
More