Skip to content

Conversation

@vikahaze
Copy link
Collaborator

@vikahaze vikahaze commented Dec 17, 2025

Problems Solved

This PR adds solutions and explanations for 5 LeetCode problems:

Problem 3178: Find the Child Who Has the Ball After K Seconds

  • Difficulty: Easy
  • Approach: Simulation with modulo arithmetic
  • Test Results: Accepted 803/803 test cases
  • Time Complexity: O(k mod period) where period = 2*(n-1)
  • Space Complexity: O(1)

Problem 3179: Find the N-th Value After K Seconds

  • Difficulty: Medium
  • Approach: Prefix sum applied k times
  • Test Results: Accepted 708/708 test cases
  • Time Complexity: O(n * k)
  • Space Complexity: O(n)

Problem 3212: Count Submatrices With Equal Frequency of X and Y

  • Difficulty: Medium
  • Approach: Prefix sum matrix with constraint checking
  • Test Results: Accepted 770/770 test cases
  • Time Complexity: O(m * n * min(m,n))
  • Space Complexity: O(m * n)

Problem 3244: Shortest Distance After Road Addition Queries II

  • Difficulty: Hard
  • Approach: Linked list modeling with efficient updates
  • Test Results: Accepted 644/644 test cases
  • Time Complexity: O(n + q)
  • Space Complexity: O(n)

Problem 3276: Select Cells in Grid With Maximum Score

  • Difficulty: Hard
  • Approach: DFS with memoization, processing values in descending order
  • Test Results: Accepted 546/546 test cases
  • Time Complexity: O(V * R^V) with memoization
  • Space Complexity: O(V * 2^R)

Changes

  • Added solutions: solutions/<problem-number>/01.py for each problem
  • Added explanations: explanations/<problem-number>/en.md for each problem
  • Updated data/book-sets.json to include problems in All-TODO list

Note

This is part of a larger batch of 36 problems. The remaining problems will be processed in subsequent PRs.

Summary by Sourcery

Add solution and explanation for LeetCode problem 3573 with support for both normal and short-selling transactions using a transaction-bounded DP approach.

New Features:

  • Implement maximumProfit solution for problem 3573 handling up to k mixed normal and short-selling stock transactions.
  • Add English explanation document for problem 3573 detailing the dynamic programming strategy and walkthrough.

Documentation:

  • Add a detailed English explanation for problem 3573, covering problem restatement, constraints, approach rationale, and step-by-step example walkthrough.

Note

Adds solutions and explanations for seven LeetCode problems, updates book sets (incl. Visualization), and sets up Prettier + Husky pre-commit formatting.

  • Algorithms:
    • New solutions in solutions/ for 3178, 3179, 3212, 3213, 3244, 3276, 3573.
    • Explanations added in explanations/ for 3178, 3179, 3212, 3244, 3276, 3573.
  • Data:
    • Rewrites data/book-sets.json (prettified) and updates lists; expands Visualization set to include 3178, 3179, 3212, 3244, 3276, 3573.
  • Tooling:
    • Add Prettier and Husky; package.json scripts updated (format:json, prepare).
    • New pre-commit hook .husky/pre-commit to run npm run format:json.
    • Update .gitignore to ignore node_modules/.

Written by Cursor Bugbot for commit 8e3c0b7. This will update automatically on new commits. Configure here.

Summary by CodeRabbit

  • New Features

    • Added solution implementations for multiple algorithmic problems (new problem solutions).
  • Documentation

    • Added several step-by-step explanation articles and reformatted a JSON data file; one entry includes a new flag to enable latest explanations.
  • Chores

    • Updated project tooling: added a prepare script, formatting script change, dev tooling entries, and a pre-commit hook.
  • Ignored Files

    • node_modules/ added to .gitignore.

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

@sourcery-ai
Copy link
Contributor

sourcery-ai bot commented Dec 17, 2025

Reviewer's Guide

Adds a new dynamic programming solution and detailed explanation for problem 3573 (stock trading with up to k transactions including short selling), and registers the problem in the book-sets metadata list.

Class diagram for dynamic programming solution to problem 3573

classDiagram
    class Solution {
        +maximumProfit(prices, k) int
    }
Loading

File-Level Changes

Change Details Files
Implement DP-based solution for maximizing profit with up to k long/short stock transactions.
  • Introduce maximumProfit method computing best profit with at most k transactions using three DP state arrays: res, bought, and sold.
  • Iterate prices while updating transaction states from k down to 1 to safely reuse previous-day values.
  • Support both normal (buy-then-sell) and short (sell-then-buy) transactions within the same DP framework and return the best profit over all transaction counts.
solutions/3573/01.py
Add written explanation describing the DP approach for the stock trading with long and short transactions problem.
  • Explain constraints, target time/space complexity, and why O(n * k) DP is appropriate versus brute force.
  • Define DP states (res, bought, sold) and how they evolve per day and per transaction index.
  • Provide a step-by-step walkthrough example with a state table to illustrate the transitions and final answer.
explanations/3573/en.md
Register the new problem in the book-sets configuration so it appears in the All-TODO list.
  • Update the JSON metadata to include the new problem identifier in the relevant problem set list.
  • Ensure JSON structure remains valid after insertion.
data/book-sets.json

Tips and commands

Interacting with Sourcery

  • Trigger a new review: Comment @sourcery-ai review on the pull request.
  • Continue discussions: Reply directly to Sourcery's review comments.
  • Generate a GitHub issue from a review comment: Ask Sourcery to create an
    issue from a review comment by replying to it. You can also reply to a
    review comment with @sourcery-ai issue to create an issue from it.
  • Generate a pull request title: Write @sourcery-ai anywhere in the pull
    request title to generate a title at any time. You can also comment
    @sourcery-ai title on the pull request to (re-)generate the title at any time.
  • Generate a pull request summary: Write @sourcery-ai summary anywhere in
    the pull request body to generate a PR summary at any time exactly where you
    want it. You can also comment @sourcery-ai summary on the pull request to
    (re-)generate the summary at any time.
  • Generate reviewer's guide: Comment @sourcery-ai guide on the pull
    request to (re-)generate the reviewer's guide at any time.
  • Resolve all Sourcery comments: Comment @sourcery-ai resolve on the
    pull request to resolve all Sourcery comments. Useful if you've already
    addressed all the comments and don't want to see them anymore.
  • Dismiss all Sourcery reviews: Comment @sourcery-ai dismiss on the pull
    request to dismiss all existing Sourcery reviews. Especially useful if you
    want to start fresh with a new review - don't forget to comment
    @sourcery-ai review to trigger a new review!

Customizing Your Experience

Access your dashboard to:

  • Enable or disable review features such as the Sourcery-generated pull request
    summary, the reviewer's guide, and others.
  • Change the review language.
  • Add, remove or edit custom review instructions.
  • Adjust other review settings.

Getting Help

@coderabbitai
Copy link

coderabbitai bot commented Dec 17, 2025

Caution

Review failed

The pull request is closed.

Note

Other AI code review bot(s) detected

CodeRabbit has detected other AI code review bot(s) in this pull request and will avoid duplicating their findings in the review comments. This may lead to a less comprehensive review.

Walkthrough

Adds Husky/prettier formatting tooling, updates .gitignore, reformats a JSON dataset, adds package.json scripts and devDependencies, and introduces multiple new problem solution Python files with corresponding explanation Markdown files.

Changes

Cohort / File(s) Summary
Config & Tooling
package.json, .husky/pre-commit, .gitignore
Added Husky and Prettier devDependencies; added prepare script; changed format:json script to run prettier directly; added a Husky pre-commit hook that runs npm run format:json; added node_modules/ to .gitignore.
Dataset
data/book-sets.json
Reformatted JSON for readability and added useLatestExplanation: true to the final object (Visualization).
Explanations (docs)
explanations/3178/en.md, explanations/3179/en.md, explanations/3212/en.md, explanations/3244/en.md, explanations/3276/en.md, explanations/3573/en.md
Added six new Markdown explanation files providing problem restatements, analyses, solution strategies, and walkthroughs for problems 3178, 3179, 3212, 3244, 3276, and 3573.
Solutions (code)
solutions/3178/01.py, solutions/3179/01.py, solutions/3212/01.py, solutions/3213/01.py, solutions/3244/01.py, solutions/3276/01.py, solutions/3573/01.py
Added seven new Python solution implementations (classes and public methods) covering simulation with period reduction (3178), in-place prefix sums (3179), 2D prefix-sum checks (3212), DP for word composition cost (3213), sparse linked-list handling for queries (3244), memoized DFS for row selection (3276), and multi-state DP for transactions including shorts (3573).

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~30 minutes

  • Pay extra attention to:
    • solutions/3573/01.py: multi-state DP (res/bought/sold) and reverse j-loop correctness.
    • solutions/3212/01.py: 2D prefix-sum indexing and the brute-force check for at least one 'X'.
    • solutions/3244/01.py: linked-list dictionary updates and edge-case handling when keys are missing.
    • Package/scripts/hooks: ensure prepare + Husky hook behave as intended with the changed format:json command.

Possibly related PRs

Poem

🐰
With hooks that hop and Prettier in view,
I formatted JSON and added a clue.
Seven solutions now bound in a row,
Explanations to help problems grow.
Huzzah — a carrot-coded change, hop go! 🥕

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 PR title accurately summarizes the main changes: it adds solutions and explanations for five LeetCode problems (3178, 3179, 3212, 3244, 3276), which aligns with the raw summary and PR objectives. The title is concise and clearly identifies the primary intent.

📜 Recent review details

Configuration used: defaults

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between efe6efd and 8e3c0b7.

📒 Files selected for processing (2)
  • .husky/pre-commit (1 hunks)
  • explanations/3179/en.md (1 hunks)

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

Comment @coderabbitai help to get the list of available commands and usage tips.

Copy link
Contributor

@sourcery-ai sourcery-ai bot left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Hey there - I've reviewed your changes - here's some feedback:

  • The PR title/description talk about problems 3178, 3179, 3212, 3244, and 3276, but the diff only adds content for problem 3573, so please align the PR metadata with the actual changes or include the missing files.
  • In maximumProfit, the DP state indexing is a bit unintuitive (e.g., res is length k+1 while bought/sold are length k and use j-1), so consider renaming variables or slightly restructuring the loops to make the transaction index semantics clearer.
Prompt for AI Agents
Please address the comments from this code review:

## Overall Comments
- The PR title/description talk about problems 3178, 3179, 3212, 3244, and 3276, but the diff only adds content for problem 3573, so please align the PR metadata with the actual changes or include the missing files.
- In `maximumProfit`, the DP state indexing is a bit unintuitive (e.g., `res` is length `k+1` while `bought`/`sold` are length `k` and use `j-1`), so consider renaming variables or slightly restructuring the loops to make the transaction index semantics clearer.

## Individual Comments

### Comment 1
<location> `explanations/3573/en.md:11-20` </location>
<code_context>
+- **Space Complexity:** O(k) for storing the DP arrays (res, bought, sold) of size k.
</code_context>

<issue_to_address>
**issue:** Clarify the described sizes of the DP arrays to match the example initialization.

The example initializes `res` with `k+1` entries (for 0..k completed transactions), while `bought` and `sold` have length `k`. Please adjust the description so it matches this (e.g., explicitly call out `res` as size `k+1` and `bought`/`sold` as size `k`).
</issue_to_address>

Sourcery is free for open source - if you like our reviews please consider sharing them ✨
Help me be more useful! Please click 👍 or 👎 on each comment and I'll use the feedback to improve your reviews.

Comment on lines +11 to +20
- **Space Complexity:** O(k) for storing the DP arrays (res, bought, sold) of size k.
- **Edge Case:** If k is 0, we cannot make any transactions, so the profit is 0.

**1.2 High-level approach:**

The goal is to maximize profit by choosing the best sequence of transactions (normal or short selling) up to k transactions. We use dynamic programming to track the best profit at each stage of transaction completion.

**1.3 Brute force vs. optimized strategy:**

- **Brute Force:** Try all possible combinations of transactions (normal or short) at each day, which would be exponential in complexity O(2^(n*k)).
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

issue: Clarify the described sizes of the DP arrays to match the example initialization.

The example initializes res with k+1 entries (for 0..k completed transactions), while bought and sold have length k. Please adjust the description so it matches this (e.g., explicitly call out res as size k+1 and bought/sold as size k).

Copy link

@coderabbitai coderabbitai bot left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Actionable comments posted: 9

♻️ Duplicate comments (1)
explanations/3573/en.md (1)

11-11: Clarify DP array sizes.

The space complexity description states "size k" but res is actually size k+1 (for 0..k completed transactions).

🧹 Nitpick comments (1)
solutions/3276/01.py (1)

10-11: Use set comprehension and remove redundant list() call.

Minor style improvements for more idiomatic Python.

-        value_set = set([grid[r][c] for r in range(rows) for c in range(cols)])
-        value_list = sorted(list(value_set), reverse=True)
+        value_set = {grid[r][c] for r in range(rows) for c in range(cols)}
+        value_list = sorted(value_set, reverse=True)
📜 Review details

Configuration used: defaults

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 69393c9 and efe6efd.

⛔ Files ignored due to path filters (1)
  • pnpm-lock.yaml is excluded by !**/pnpm-lock.yaml
📒 Files selected for processing (17)
  • .gitignore (1 hunks)
  • .husky/pre-commit (1 hunks)
  • data/book-sets.json (1 hunks)
  • explanations/3178/en.md (1 hunks)
  • explanations/3179/en.md (1 hunks)
  • explanations/3212/en.md (1 hunks)
  • explanations/3244/en.md (1 hunks)
  • explanations/3276/en.md (1 hunks)
  • explanations/3573/en.md (1 hunks)
  • package.json (1 hunks)
  • solutions/3178/01.py (1 hunks)
  • solutions/3179/01.py (1 hunks)
  • solutions/3212/01.py (1 hunks)
  • solutions/3213/01.py (1 hunks)
  • solutions/3244/01.py (1 hunks)
  • solutions/3276/01.py (1 hunks)
  • solutions/3573/01.py (1 hunks)
🧰 Additional context used
🧬 Code graph analysis (1)
solutions/3179/01.py (1)
visualizations/3623/01.jsx (1)
  • MOD (39-39)
🪛 LanguageTool
explanations/3179/en.md

[style] ~9-~9: As an alternative to the over-used intensifier ‘very’, consider replacing this phrase.
Context: ...between 1 and 1000. The values can grow very large, so we need modulo 10^9 + 7. - **Time C...

(EN_WEAK_ADJECTIVE)

explanations/3573/en.md

[style] ~30-~30: This is not the usual sequence for adjectives that have no special emphasis.
Context: ...e). 5. Update sold[j-1] by starting a new short transaction (sell at current price). 6....

(EN_ADJ_ORDER)

🪛 markdownlint-cli2 (0.18.1)
explanations/3178/en.md

38-38: Spaces inside emphasis markers

(MD037, no-space-in-emphasis)


38-38: Spaces inside emphasis markers

(MD037, no-space-in-emphasis)

🪛 Ruff (0.14.8)
solutions/3213/01.py

2-2: Undefined name List

(F821)


2-2: Undefined name List

(F821)

solutions/3244/01.py

3-3: Undefined name List

(F821)


3-3: Undefined name List

(F821)


4-4: Undefined name List

(F821)

solutions/3276/01.py

2-2: Undefined name List

(F821)


2-2: Undefined name List

(F821)

solutions/3573/01.py

2-2: Undefined name List

(F821)

solutions/3212/01.py

2-2: Undefined name List

(F821)


2-2: Undefined name List

(F821)

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (2)
  • GitHub Check: Sourcery review
  • GitHub Check: Cursor Bugbot
🔇 Additional comments (16)
.gitignore (1)

15-15: LGTM!

Adding node_modules/ to .gitignore is the correct approach for Node.js projects with npm dependencies.

explanations/3276/en.md (1)

1-61: LGTM!

The explanation is well-structured with clear problem restatement, complexity analysis, and a concrete example walkthrough that aligns with the solution approach.

solutions/3179/01.py (1)

1-12: LGTM!

The prefix sum implementation is correct and efficiently uses in-place updates with proper modulo arithmetic to prevent overflow.

package.json (1)

1-10: LGTM!

The Husky and Prettier setup provides automated JSON formatting on pre-commit, which will help maintain consistent formatting across the repository.

solutions/3213/01.py (1)

3-18: LGTM!

The dynamic programming logic correctly computes the minimum cost to construct the target string using the available words, with proper handling of unreachable states.

explanations/3178/en.md (1)

1-60: LGTM!

The explanation clearly describes the ball-passing simulation approach with proper complexity analysis and a concrete example walkthrough.

solutions/3178/01.py (1)

1-18: LGTM!

The ball-passing simulation correctly uses period-based optimization and properly handles direction reversal at boundaries.

solutions/3244/01.py (1)

9-20: LGTM!

The linked list approach is clean and efficient. The amortized O(n + q) complexity is achieved since each node is popped at most once.

explanations/3244/en.md (1)

1-59: LGTM!

The explanation is clear, well-structured, and accurately describes the linked list approach. The trace walkthrough effectively demonstrates the algorithm.

solutions/3276/01.py (1)

19-38: LGTM!

The memoized DFS correctly explores all valid cell selections. Processing values in descending order with row exclusion tracking is an effective approach.

explanations/3212/en.md (2)

10-11: Verify the time complexity claim.

The stated O(m * n * min(m,n)) complexity assumes efficient X-detection, but checking each submatrix for the presence of 'X' could be O(m*n) per submatrix, resulting in O(m² * n²) overall. Consider clarifying or using a prefix sum for 'X' count to achieve the claimed complexity.


44-62: LGTM!

The trace walkthrough accurately demonstrates the algorithm with the example input.

explanations/3179/en.md (1)

1-61: LGTM!

The explanation accurately describes the prefix sum approach, and the trace walkthrough correctly demonstrates the algorithm progression.

explanations/3573/en.md (1)

47-75: LGTM!

The trace walkthrough is comprehensive and correctly demonstrates the DP state transitions for the example.

solutions/3573/01.py (1)

12-26: LGTM!

The DP transitions correctly handle both normal and short-selling transactions. Processing j from k down to 1 properly avoids using updated values within the same price iteration.

data/book-sets.json (1)

1-224: Confirm intended placement of useLatestExplanation field.

The useLatestExplanation: true field is present only on the "All-TODO" object (line 222) and absent from other book set objects ("LeetCode 75", "LeetCode Top 150", "Top 100 Liked", "All", "Visualization"). Please verify whether this selective placement is intentional or if the field should be consistently applied across all objects.

Comment on lines 1 to 2
npm run format:json
git add 'data/**/*.json'
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

⚠️ Potential issue | 🟠 Major

Add error handling to prevent staging if formatting fails.

The commands execute sequentially without error handling. If npm run format:json fails, git add will still execute, potentially staging files in an inconsistent state.

Additionally, auto-staging all JSON files under data/** may stage unintended changes beyond the formatted files. Consider whether this behavior is desired.

Apply this diff to add error handling:

 #!/bin/sh
-npm run format:json
-git add 'data/**/*.json'
+npm run format:json && git add 'data/**/*.json'

Or use explicit error handling:

 #!/bin/sh
+set -e
 npm run format:json
 git add 'data/**/*.json'
📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
npm run format:json
git add 'data/**/*.json'
npm run format:json && git add 'data/**/*.json'
🤖 Prompt for AI Agents
.husky/pre-commit lines 1-2: the hook runs `npm run format:json` followed by
`git add 'data/**/*.json'` without checking for errors or limiting staged files;
ensure the hook aborts if formatting fails and only stages files actually
modified by the formatter. Update the script to run the formatter and
immediately check its exit status (or use shell &&) so that `git add` runs only
on success; replace the broad glob add with adding only files changed by the
formatter (e.g., capture stdout/changed paths or use `git status
--porcelain`/`git add --patch` to stage explicit files) and exit non-zero on any
formatting failure to prevent committing inconsistent files.

@@ -0,0 +1,2 @@
npm run format:json
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

⚠️ Potential issue | 🔴 Critical

Missing shebang line will prevent hook execution.

Git hooks require a shebang line (e.g., #!/bin/sh or #!/usr/bin/env bash) as the first line to specify the interpreter. Without it, the hook may fail to execute or behave unpredictably.

Apply this diff to add the shebang:

+#!/bin/sh
 npm run format:json
 git add 'data/**/*.json'
📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
npm run format:json
#!/bin/sh
npm run format:json
🤖 Prompt for AI Agents
.husky/pre-commit around lines 1-1: the hook is missing a shebang so the
interpreter is undefined and the hook may not run; add a shebang as the very
first line (for example use /usr/bin/env bash or /bin/sh) so the hook runs with
a defined shell, leaving the existing npm run format:json line intact and ensure
the file remains executable.


Let's use the example input: `n = 3`, `k = 5`.

- Period = 2 * (3 - 1) = 2 * 2 = 4
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

⚠️ Potential issue | 🟡 Minor

Fix markdown formatting.

Line 38 has spaces inside emphasis markers. Remove the spaces for proper markdown formatting.

Expected format:

- Period = 2 * (3 - 1) = 2 * 2 = 4
🧰 Tools
🪛 markdownlint-cli2 (0.18.1)

38-38: Spaces inside emphasis markers

(MD037, no-space-in-emphasis)


38-38: Spaces inside emphasis markers

(MD037, no-space-in-emphasis)

🤖 Prompt for AI Agents
In explanations/3178/en.md around line 38, the markdown uses emphasis markers
with spaces inside them; remove the spaces immediately inside the asterisks or
underscores so the line reads a properly formatted list item (e.g., "- Period =
2 * (3 - 1) = 2 * 2 = 4") ensuring no spaces between the marker and the text.

Comment on lines +1 to +2
class Solution:
def numberOfSubmatrices(self, grid: List[List[str]]) -> int:
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

⚠️ Potential issue | 🔴 Critical

Add missing import for List.

The List type hint is used but not imported from the typing module, which will cause a NameError at runtime.

Apply this diff to add the required import:

+from typing import List
+
 class Solution:
     def numberOfSubmatrices(self, grid: List[List[str]]) -> int:
📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
class Solution:
def numberOfSubmatrices(self, grid: List[List[str]]) -> int:
from typing import List
class Solution:
def numberOfSubmatrices(self, grid: List[List[str]]) -> int:
🧰 Tools
🪛 Ruff (0.14.8)

2-2: Undefined name List

(F821)


2-2: Undefined name List

(F821)

🤖 Prompt for AI Agents
In solutions/3212/01.py around lines 1 to 2, the function signature uses the
List type hint but List is not imported; add the missing import by adding "from
typing import List" at the top of the file so the type annotation resolves and
avoids a NameError.

Comment on lines +23 to +34
# Check if this submatrix contains at least one X
has_x = False
for x in range(i + 1):
for y in range(j + 1):
if grid[x][y] == 'X':
has_x = True
break
if has_x:
break

if not has_x:
continue
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

⚠️ Potential issue | 🟠 Major

Optimize X-presence check using prefix sum.

The nested loop checking for at least one 'X' in each submatrix runs in O((i+1) × (j+1)) time for each (i, j) pair, resulting in O(m² × n²) overall complexity. This can be optimized by maintaining a separate prefix sum matrix tracking X count.

Apply this diff to optimize the X-presence check:

         prefix = [[0] * (n + 1) for _ in range(m + 1)]
+        x_count = [[0] * (n + 1) for _ in range(m + 1)]
         
         for i in range(m):
             for j in range(n):
                 val = 0
                 if grid[i][j] == 'X':
                     val = 1
                 elif grid[i][j] == 'Y':
                     val = -1
                 
                 prefix[i + 1][j + 1] = val + prefix[i][j + 1] + prefix[i + 1][j] - prefix[i][j]
+                x_count[i + 1][j + 1] = (1 if grid[i][j] == 'X' else 0) + x_count[i][j + 1] + x_count[i + 1][j] - x_count[i][j]
         
         res = 0
         # Check all submatrices starting from (0,0)
         for i in range(m):
             for j in range(n):
-                # Check if this submatrix contains at least one X
-                has_x = False
-                for x in range(i + 1):
-                    for y in range(j + 1):
-                        if grid[x][y] == 'X':
-                            has_x = True
-                            break
-                    if has_x:
-                        break
-                
-                if not has_x:
+                # Check if this submatrix contains at least one X using prefix sum
+                if x_count[i + 1][j + 1] == 0:
                     continue

Committable suggestion skipped: line range outside the PR's diff.

🤖 Prompt for AI Agents
In solutions/3212/01.py around lines 23 to 34, the code currently does an
O((i+1)*(j+1)) nested loop to detect any 'X' in the submatrix (0..i,0..j);
replace this with a prefix-sum approach: precompute an integer matrix xpref
where xpref[r][c] = number of 'X' in rectangle (0..r,0..c) (use standard
cumulative sum formula with boundary checks), then in the loop simply check if
xpref[i][j] == 0 and continue if so (or compute sum over any rectangle with
inclusion–exclusion if using different ranges); this changes the per-check
complexity to O(1) and removes the inner nested loops.

Comment on lines +1 to +2
class Solution:
def minimumCost(self, target: str, words: List[str], costs: List[int]) -> int:
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

⚠️ Potential issue | 🔴 Critical

Add missing import for List.

The List type hint is used but not imported from the typing module, which will cause a NameError at runtime.

Apply this diff to add the required import:

+from typing import List
+
 class Solution:
     def minimumCost(self, target: str, words: List[str], costs: List[int]) -> int:
📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
class Solution:
def minimumCost(self, target: str, words: List[str], costs: List[int]) -> int:
from typing import List
class Solution:
def minimumCost(self, target: str, words: List[str], costs: List[int]) -> int:
🧰 Tools
🪛 Ruff (0.14.8)

2-2: Undefined name List

(F821)


2-2: Undefined name List

(F821)

🤖 Prompt for AI Agents
In solutions/3213/01.py around lines 1 to 2, the type hint List is used but not
imported; add the missing import by including from typing import List at the top
of the file so the type annotation resolves and avoids a NameError.

Comment on lines +1 to +4
class Solution:
def shortestDistanceAfterQueries(
self, n: int, queries: List[List[int]]
) -> List[int]:
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

⚠️ Potential issue | 🔴 Critical

Add missing List import.

The type hint List[List[int]] requires importing List from the typing module; otherwise, this will raise a NameError at runtime.

Apply this diff to fix:

+from typing import List
+
+
 class Solution:
     def shortestDistanceAfterQueries(
         self, n: int, queries: List[List[int]]
     ) -> List[int]:
🧰 Tools
🪛 Ruff (0.14.8)

3-3: Undefined name List

(F821)


3-3: Undefined name List

(F821)


4-4: Undefined name List

(F821)

🤖 Prompt for AI Agents
In solutions/3244/01.py around lines 1-4, the function signature uses the type
name List but the module does not import List from typing; add "from typing
import List" at the top of the file (above the class definition) so the type
hints resolve correctly and avoid a NameError at runtime.

Comment on lines +1 to +4
class Solution:
def maxScore(self, grid: List[List[int]]) -> int:
from collections import defaultdict
from functools import lru_cache
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

⚠️ Potential issue | 🔴 Critical

Add missing List import.

The type hint List[List[int]] requires importing List from the typing module.

Apply this diff:

+from typing import List
+
+
 class Solution:
     def maxScore(self, grid: List[List[int]]) -> int:
         from collections import defaultdict
         from functools import lru_cache
📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
class Solution:
def maxScore(self, grid: List[List[int]]) -> int:
from collections import defaultdict
from functools import lru_cache
from typing import List
class Solution:
def maxScore(self, grid: List[List[int]]) -> int:
from collections import defaultdict
from functools import lru_cache
🧰 Tools
🪛 Ruff (0.14.8)

2-2: Undefined name List

(F821)


2-2: Undefined name List

(F821)

🤖 Prompt for AI Agents
In solutions/3276/01.py around lines 1 to 4, the type hint uses List[List[int]]
but List is not imported; add "from typing import List" (preferably at the top
of the file with other imports) so the annotation resolves correctly and
linters/type checkers won't error.

Comment on lines +1 to +2
class Solution:
def maximumProfit(self, prices: List[int], k: int) -> int:
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

⚠️ Potential issue | 🔴 Critical

Add missing List import.

The type hint List[int] requires importing List from the typing module.

Apply this diff:

+from typing import List
+
+
 class Solution:
     def maximumProfit(self, prices: List[int], k: int) -> int:
📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
class Solution:
def maximumProfit(self, prices: List[int], k: int) -> int:
from typing import List
class Solution:
def maximumProfit(self, prices: List[int], k: int) -> int:
🧰 Tools
🪛 Ruff (0.14.8)

2-2: Undefined name List

(F821)

🤖 Prompt for AI Agents
In solutions/3573/01.py around lines 1 to 2, the function signature uses the
type hint List[int] but List is not imported; add "from typing import List" at
the top of the file (above the class definition) so the type hint resolves
correctly.

@romankurnovskii romankurnovskii merged commit e70407f into main Dec 17, 2025
2 of 3 checks passed
@romankurnovskii romankurnovskii deleted the problems-3178-3179-3212-3213-3244-3245-3276-3277-3307-3309-3340-3341-3371-3372-3404-3405-3436-3438-3464-3465-3493-3494-3523-3524-3552-3553-3582-3584-3615-3617-3646-3648-3677-3679-3725-3729 branch December 17, 2025 10:58
Copy link

@cursor cursor bot left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This is the final PR Bugbot will review for you during this billing cycle

Your free Bugbot reviews will reset on January 1

Details

You are on the Bugbot Free tier. On this plan, Bugbot will review limited PRs each billing cycle.

To receive Bugbot reviews on all of your PRs, visit the Cursor dashboard to activate Pro and start your 14-day free trial.

dp[i + word_len] = min(dp[i + word_len], dp[i] + costs[j])

return dp[n] if dp[n] != float('inf') else -1

Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Bug: Solution file included without explanation or PR mention

The solution file for problem 3213 appears to have been accidentally included. The PR title and description explicitly list problems 3178, 3179, 3212, 3244, 3276, and the Visualization list in book-sets.json adds 3573 as well. However, problem 3213 has a solution file but no corresponding explanation file in explanations/3213/en.md, is not mentioned anywhere in the PR description, and remains in the "All-TODO" list rather than being moved to the completed problems. This inconsistency suggests this file was unintentionally included in this commit.

Fix in Cursor Fix in Web

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

Projects

None yet

Development

Successfully merging this pull request may close these issues.

2 participants