LeetCode-2975: Maximum Square Area by Removing Fences From a Field

[WazedKhan]

Summary by CodeRabbit

• New Features
  • Added a solution that computes the largest possible square area obtainable by removing horizontal and vertical fences within an m×n field.
  • Returns -1 when no valid square exists; otherwise returns the square area (applies modulo 1,000,000,007).
  • Handles boundary conditions and documents expected inputs.

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[coderabbitai]

📝 Walkthrough

Walkthrough

Introduces LeetCode/medium.py with a Solution class and maximizeSquareArea method that computes the largest square side formed by horizontal and vertical fence positions within an m×n field, returning the squared side length modulo 1,000,000,007 or -1 if none exists.

Changes

Cohort / File(s)	Summary
New LeetCode Medium Problem LeetCode/medium.py	Added Solution class with maximizeSquareArea(self, m: int, n: int, hFences: List[int], vFences: List[int]) -> int. Builds boundary-inclusive fence coordinate lists, computes horizontal distances, checks matching vertical distances, returns max side² % 1_000_000_007 or -1.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Poem

🐰 I count the posts from end to start,
Distances dance and play their part.
Squares emerge where lines align,
I hop, I cheer — that side is mine! ✨

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 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 describes the main change: implementing a LeetCode solution (problem 2975) for finding the maximum square area by removing fences from a field.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

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✨ Finishing touches

• 📝 Generate docstrings

---

🧹 Recent nitpick comments

LeetCode/medium.py (2)

7-20: Move the misplaced comment.

The comment # Add boundaries on line 8 should be moved to line 21 where the boundary addition actually occurs. Per PEP 257, the docstring should be the first statement after the function definition.

✨ Suggested fix

     def maximizeSquareArea(self, m: int, n: int, hFences: List[int], vFences: List[int]) -> int:
-        # Add boundaries
         """
         This function calculates the maximum square area that can be formed by removing fences from a field of size m x n.

         Parameters:
         m (int): The width of the field
         n (int): The height of the field
         hFences (List[int]): A list of horizontal fence positions
         vFences (List[int]): A list of vertical fence positions

         Returns:
         int: The maximum square area that can be formed, or -1 if it is not possible
         """
+        # Add boundaries
         h = sorted([1] + hFences + [m])

---

21-22: Consider using list unpacking for cleaner syntax.

As flagged by Ruff (RUF005), unpacking is more idiomatic and slightly more efficient than concatenation.

✨ Suggested fix

-        h = sorted([1] + hFences + [m])
-        v = sorted([1] + vFences + [n])
+        h = sorted([1, *hFences, m])
+        v = sorted([1, *vFences, n])

---

📜 Recent review details

Configuration used: defaults

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 11f9604 and 1bc0ff2.

📒 Files selected for processing (1)

• LeetCode/medium.py

🧰 Additional context used

🪛 Ruff (0.14.11)

LeetCode/medium.py

21-21: Consider [1, *hFences, m] instead of concatenation

Replace with [1, *hFences, m]

(RUF005)

---

22-22: Consider [1, *vFences, n] instead of concatenation

Replace with [1, *vFences, n]

(RUF005)

🔇 Additional comments (3)

LeetCode/medium.py (3)

1-6: LGTM!

The import and class structure are correct for the LeetCode solution.

---

24-35: LGTM!

The algorithm correctly finds the maximum common distance between fence positions in both directions. Using a set for horizontal distances enables efficient O(1) lookups during the vertical pass. The O(k²) complexity is acceptable given the problem constraints (k ≤ 602).

---

37-38: The modulo precedence issue has been correctly fixed.

The use of a named MOD constant properly addresses the operator precedence bug flagged in previous reviews. The expression now correctly computes (max_dist * max_dist) % (10**9 + 7).

_{✏️ Tip: You can disable this entire section by setting review_details to false in your review settings.}

---

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[coderabbitai]

Actionable comments posted: 2

🤖 Fix all issues with AI agents

In `@LeetCode/medium.py`:
- Line 37: The return expression uses incorrect operator precedence causing
modulo to apply to 10**9 instead of 10**9+7; update the return in the function
where the current line is "return -1 if max_dist == 0 else (max_dist * max_dist)
% 10**9 + 7" to apply modulo correctly as (max_dist * max_dist) % (10**9 + 7)
(keeping the -1 when max_dist==0).
- Around line 24-35: The modulo expression around the squared maximum distance
is using wrong precedence; update the calculation that currently uses (max_dist
* max_dist) % 10**9 + 7 to apply the modulus correctly by parenthesizing the
modulus: use (max_dist * max_dist) % (10**9 + 7). Locate where max_dist is
squared and returned/used and replace the existing expression so the entire
modulus value 10**9 + 7 is grouped.

📜 Review details

Configuration used: defaults

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between b0ff36d and 11f9604.

📒 Files selected for processing (1)

• LeetCode/medium.py

🧰 Additional context used

🪛 Ruff (0.14.11)

LeetCode/medium.py

21-21: Consider [1, *hFences, m] instead of concatenation

Replace with [1, *hFences, m]

(RUF005)

---

22-22: Consider [1, *vFences, n] instead of concatenation

Replace with [1, *vFences, n]

(RUF005)

_{✏️ Tip: You can disable this entire section by setting review_details to false in your review settings.}