Add solutions and explanations for problems 3676, 3679, 3680, 3685, 3689, 3747, 3753, 3769, 3774, 3775, 3776, 3777 #120
Conversation
…689, 3747, 3753, 3769, 3774, 3775, 3776, 3777
Reviewer's GuideAdds accepted solutions and detailed explanations for a batch of recent LeetCode problems, replaces two brute‑force solutions (3753, 3747) with efficient digit-DP/combinatorial implementations, introduces several new problem-specific solutions (including data-structure/greedy based ones), and adds a utility script to sync problem metadata from the LeetCode GraphQL API into data/leetcode-problems.json. Class diagram for FenwickTree and Solution for problem 3777classDiagram
class FenwickTree {
+int[] tree
+FenwickTree(size int)
+add(i int, delta int) void
+query(i int) int
}
class Solution_3777 {
+minDeletions(s str, queries List_List_int) List_int
}
Solution_3777 *-- FenwickTree
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WalkthroughAdds gitignore entries for Python artifacts, introduces a new script for fetching and merging LeetCode problems via GraphQL API, and commits 10 new LeetCode problem solutions with detailed explanations spanning diverse algorithms including digit DP, monotonic stacks, Fenwick trees, and greedy strategies. Changes
Sequence DiagramsequenceDiagram
participant Script as update_problems_from_leetcode.py
participant API as LeetCode GraphQL API
participant FS as File System
participant Processor as Data Processor
Script->>FS: load_existing_json()
FS-->>Script: existing_data
loop Batch Pagination (skip=0, limit=50)
Script->>API: fetch_problems_batch(limit, skip)
API-->>Script: problems_batch + metadata
Script->>Script: rate limit delay
alt HTTP Error
Script->>Script: log error, continue
else Parse Error
Script->>Script: handle gracefully
end
end
Script->>Processor: map_tags_to_category() & map_difficulty()
Processor-->>Script: normalized_problems
Script->>Processor: Merge logic
Processor->>Processor: Add missing problems
Processor->>Processor: Update existing entries
Processor-->>Script: merged_data
Script->>FS: save_json(merged_data)
FS-->>Script: write complete
Script->>Script: Print summary (missing count, updated count, samples)
Estimated code review effort🎯 3 (Moderate) | ⏱️ ~25 minutes
Possibly related PRs
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Pre-merge checks and finishing touches❌ Failed checks (1 warning)
✅ Passed checks (2 passed)
✨ Finishing touches
🧪 Generate unit tests (beta)
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Hey there - I've reviewed your changes and found some issues that need to be addressed.
- In
Solution.totalWaviness(3753),_total_waviness_upto(num1 - 1)will be called with a negative argument whennum1 == 0or1, which breaks the digit handling; consider short‑circuiting for non‑positive inputs in the helper. - In
Solution.minDeletions(3777), the Fenwick tree updates on flips (bit.add(i, 1 if A[i] == A[i - 1] else -1)) don’t account for the previous violation state, so they can apply the wrong delta; you likely need to compute old/new violation flags and update by(new - old)instead of blindly adding ±1. - In
Solution.minMoves(3776), the logic only balances the first negative index using nearby positives, so multiple negative positions (or the need to pass surplus through intermediate nodes) are not handled; consider a prefix-sum or cumulative imbalance approach that accounts for all positions on the circle rather than a single negative index.
Prompt for AI Agents
Please address the comments from this code review:
## Overall Comments
- In `Solution.totalWaviness` (3753), `_total_waviness_upto(num1 - 1)` will be called with a negative argument when `num1 == 0` or `1`, which breaks the digit handling; consider short‑circuiting for non‑positive inputs in the helper.
- In `Solution.minDeletions` (3777), the Fenwick tree updates on flips (`bit.add(i, 1 if A[i] == A[i - 1] else -1)`) don’t account for the previous violation state, so they can apply the wrong delta; you likely need to compute old/new violation flags and update by `(new - old)` instead of blindly adding ±1.
- In `Solution.minMoves` (3776), the logic only balances the first negative index using nearby positives, so multiple negative positions (or the need to pass surplus through intermediate nodes) are not handled; consider a prefix-sum or cumulative imbalance approach that accounts for all positions on the circle rather than a single negative index.
## Individual Comments
### Comment 1
<location> `solutions/3777/01.py:29-36` </location>
<code_context>
+ bit.add(i + 1, 1)
+
+ res = []
+ for q in queries:
+ if q[0] == 1:
+ # Flip operation
+ i = q[1]
+ A[i] ^= 1
+ # Update violations at position i and i+1
+ if i > 0:
+ bit.add(i, 1 if A[i] == A[i - 1] else -1)
+ if i < n - 1:
+ bit.add(i + 1, 1 if A[i] == A[i + 1] else -1)
</code_context>
<issue_to_address>
**issue (bug_risk):** Fenwick tree updates on flips don’t account for previous violation state, leading to incorrect counts.
On a flip, you’re updating the BIT based only on the new equality, not on how it changed. If a pair stays equal before and after the flip, you’re incrementing twice; if it switches from equal→unequal or vice versa, the sign may be wrong. Instead, compute the old and new violation flags and update by their difference, e.g.:
```python
old_v = int(prev_A_i == A[i - 1]) # or read from BIT / cached state
new_v = int(A[i] == A[i - 1])
bit.add(i, new_v - old_v)
```
and likewise for the `(i, i + 1)` pair, so the tree always matches the true count of adjacent-equal pairs.
</issue_to_address>
### Comment 2
<location> `solutions/3776/01.py:31-40` </location>
<code_context>
+**2.4 Sort Positive Indices by Distance:**
+
+```python
+positives = []
+for i in range(n):
+ if balance[i] > 0:
</code_context>
<issue_to_address>
**issue (bug_risk):** Greedy transfer logic doesn’t update balances and only handles a single negative index, which likely miscomputes minimal moves.
The logic assumes a single negative index and greedily pulls from nearby positives without ever mutating `balance` or tracking remaining surplus per index. This breaks flow conservation and can produce wrong move counts when there are multiple deficits or when transfers must pass through intermediates. To get correct minimal moves on a ring, either (1) treat this as flow and use prefix sums of net balances, or (2) actually update `balance[idx]` as you transfer and support multiple negative indices. As implemented, results will be incorrect on more complex cases.
</issue_to_address>
### Comment 3
<location> `solutions/3679/01.py:3-11` </location>
<code_context>
+class Solution:
+ def minArrivalsToDiscard(self, arrivals: List[int], w: int, m: int) -> int:
+ mx = max(arrivals) if arrivals else 0
+ ctr = [0] * (mx + 1)
+ res = 0
+
+ for idx, item in enumerate(arrivals):
+ # Remove item that left the window
+ if idx >= w:
+ left_item = arrivals[idx - w]
+ if left_item != 0: # Only decrement if it was kept
+ ctr[left_item] -= 1
+
</code_context>
<issue_to_address>
**issue (bug_risk):** Using `0` as a sentinel for discarded arrivals can conflict with legitimate zero values.
This relies on `0` never being a valid arrival value: discards are written as `0`, and the counter is only decremented when `left_item != 0`. If `0` is allowed, real zeros are miscounted and windows with many zeros will violate the intended `m`-based behavior. Consider tracking discards separately (e.g., a boolean array) or using a sentinel value outside the input range.
</issue_to_address>
### Comment 4
<location> `scripts/update_problems_from_leetcode.py:148-157` </location>
<code_context>
+ payload = {"query": PROBLEMS_QUERY, "variables": variables}
+
+ try:
+ response = requests.post(
+ LEETCODE_API_URL,
+ json=payload,
+ headers={
+ "Content-Type": "application/json",
+ "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36",
+ },
+ timeout=30,
+ )
+ response.raise_for_status()
+ return response.json()
+ except requests.exceptions.RequestException as e:
+ print(f"Error fetching problems (skip={skip}, limit={limit}): {e}")
</code_context>
<issue_to_address>
**suggestion (bug_risk):** LeetCode GraphQL error payloads are not checked, which can silently corrupt local JSON.
This treats any 2xx response as valid, but the GraphQL API can return HTTP 200 with an `errors` field and missing/partial `data`. That can lead to writing incomplete or incorrect entries to `leetcode-problems.json`. Consider checking for an `errors` key (and expected `data` shape) in the JSON before using `data["problemsetQuestionList"]`, and log/abort/retry when errors are present.
Suggested implementation:
```python
payload = {"query": PROBLEMS_QUERY, "variables": variables}
try:
response = requests.post(
LEETCODE_API_URL,
json=payload,
headers={
"Content-Type": "application/json",
"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36",
},
timeout=30,
)
response.raise_for_status()
data = response.json()
# LeetCode GraphQL can return HTTP 200 with logical errors in the "errors" field.
# Treat such responses as failures so they don't corrupt the local JSON cache.
if "errors" in data:
print(
f"Error fetching problems (skip={skip}, limit={limit}): "
f"GraphQL errors: {data['errors']}"
)
return None
# Validate expected GraphQL data shape before using it downstream.
problemset = data.get("data", {}).get("problemsetQuestionList")
if problemset is None:
print(
f"Error fetching problems (skip={skip}, limit={limit}): "
"missing 'data.problemsetQuestionList' in response"
)
return None
return data
except requests.exceptions.RequestException as e:
print(f"Error fetching problems (skip={skip}, limit={limit}): {e}")
return None
```
1. Ensure any caller (e.g. `fetch_all_problems`) treats a `None` return value from this function as a failed batch and avoids writing partial results to `leetcode-problems.json`. Typically this means checking `if not result: break` or logging and retrying the batch instead of assuming `result["data"]["problemsetQuestionList"]` is always present.
2. If you have structured logging elsewhere in the script, you may want to replace the `print(...)` calls with your logger for consistency.
</issue_to_address>Help me be more useful! Please click 👍 or 👎 on each comment and I'll use the feedback to improve your reviews.
| for q in queries: | ||
| if q[0] == 1: | ||
| # Flip operation | ||
| i = q[1] | ||
| A[i] ^= 1 | ||
| # Update violations at position i and i+1 | ||
| if i > 0: | ||
| bit.add(i, 1 if A[i] == A[i - 1] else -1) |
There was a problem hiding this comment.
issue (bug_risk): Fenwick tree updates on flips don’t account for previous violation state, leading to incorrect counts.
On a flip, you’re updating the BIT based only on the new equality, not on how it changed. If a pair stays equal before and after the flip, you’re incrementing twice; if it switches from equal→unequal or vice versa, the sign may be wrong. Instead, compute the old and new violation flags and update by their difference, e.g.:
old_v = int(prev_A_i == A[i - 1]) # or read from BIT / cached state
new_v = int(A[i] == A[i - 1])
bit.add(i, new_v - old_v)and likewise for the (i, i + 1) pair, so the tree always matches the true count of adjacent-equal pairs.
| positives = [] | ||
| for i in range(n): | ||
| if balance[i] > 0: | ||
| # Calculate circular distance | ||
| dist1 = (i - neg_idx) % n | ||
| dist2 = (neg_idx - i) % n | ||
| dist = min(dist1, dist2) | ||
| positives.append((dist, i, balance[i])) | ||
|
|
||
| positives.sort() |
There was a problem hiding this comment.
issue (bug_risk): Greedy transfer logic doesn’t update balances and only handles a single negative index, which likely miscomputes minimal moves.
The logic assumes a single negative index and greedily pulls from nearby positives without ever mutating balance or tracking remaining surplus per index. This breaks flow conservation and can produce wrong move counts when there are multiple deficits or when transfers must pass through intermediates. To get correct minimal moves on a ring, either (1) treat this as flow and use prefix sums of net balances, or (2) actually update balance[idx] as you transfer and support multiple negative indices. As implemented, results will be incorrect on more complex cases.
| mx = max(arrivals) if arrivals else 0 | ||
| ctr = [0] * (mx + 1) | ||
| res = 0 | ||
|
|
||
| for idx, item in enumerate(arrivals): | ||
| # Remove item that left the window | ||
| if idx >= w: | ||
| left_item = arrivals[idx - w] | ||
| if left_item != 0: # Only decrement if it was kept |
There was a problem hiding this comment.
issue (bug_risk): Using 0 as a sentinel for discarded arrivals can conflict with legitimate zero values.
This relies on 0 never being a valid arrival value: discards are written as 0, and the counter is only decremented when left_item != 0. If 0 is allowed, real zeros are miscounted and windows with many zeros will violate the intended m-based behavior. Consider tracking discards separately (e.g., a boolean array) or using a sentinel value outside the input range.
| response = requests.post( | ||
| LEETCODE_API_URL, | ||
| json=payload, | ||
| headers={ | ||
| "Content-Type": "application/json", | ||
| "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36", | ||
| }, | ||
| timeout=30, | ||
| ) | ||
| response.raise_for_status() |
There was a problem hiding this comment.
suggestion (bug_risk): LeetCode GraphQL error payloads are not checked, which can silently corrupt local JSON.
This treats any 2xx response as valid, but the GraphQL API can return HTTP 200 with an errors field and missing/partial data. That can lead to writing incomplete or incorrect entries to leetcode-problems.json. Consider checking for an errors key (and expected data shape) in the JSON before using data["problemsetQuestionList"], and log/abort/retry when errors are present.
Suggested implementation:
payload = {"query": PROBLEMS_QUERY, "variables": variables}
try:
response = requests.post(
LEETCODE_API_URL,
json=payload,
headers={
"Content-Type": "application/json",
"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36",
},
timeout=30,
)
response.raise_for_status()
data = response.json()
# LeetCode GraphQL can return HTTP 200 with logical errors in the "errors" field.
# Treat such responses as failures so they don't corrupt the local JSON cache.
if "errors" in data:
print(
f"Error fetching problems (skip={skip}, limit={limit}): "
f"GraphQL errors: {data['errors']}"
)
return None
# Validate expected GraphQL data shape before using it downstream.
problemset = data.get("data", {}).get("problemsetQuestionList")
if problemset is None:
print(
f"Error fetching problems (skip={skip}, limit={limit}): "
"missing 'data.problemsetQuestionList' in response"
)
return None
return data
except requests.exceptions.RequestException as e:
print(f"Error fetching problems (skip={skip}, limit={limit}): {e}")
return None- Ensure any caller (e.g.
fetch_all_problems) treats aNonereturn value from this function as a failed batch and avoids writing partial results toleetcode-problems.json. Typically this means checkingif not result: breakor logging and retrying the batch instead of assumingresult["data"]["problemsetQuestionList"]is always present. - If you have structured logging elsewhere in the script, you may want to replace the
print(...)calls with your logger for consistency.
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Actionable comments posted: 9
🧹 Nitpick comments (10)
explanations/3769/en.md (1)
52-54: Space complexity claim is inconsistent with the code example.The explanation claims O(1) space complexity for "in-place sort" (lines 11, 68), but the code example uses
sorted()which creates a new list and returns it, requiring O(n) space. If truly in-place sorting is intended, usenums.sort(key=...)instead.Either update the space complexity to O(n), or change the code example to:
-return sorted(nums, key=lambda x: (binary_reflection(x), x)) +nums.sort(key=lambda x: (binary_reflection(x), x)) +return numsAlso applies to: 67-68
explanations/3676/en.md (1)
54-54: Clarify the reasoning for bowl formation.The statement "all elements between
landrare also <=nums[l]" is imprecise. Whenlis popped, elements betweenlandrhave already been popped from the stack (they were pushed afterland popped beforel). The key insight is that popped elements had values ≤ current value, so the bowl condition holds because those intermediate elements were strictly smaller than both endpoints.Consider clarifying this reasoning for accuracy.
solutions/3676/01.py (1)
9-9: Consider renaming ambiguous variablel.The variable
lcan be confused with the digit1in some fonts. Consider usingleftorleft_idxfor clarity.- l = stack.pop() - if r - l + 1 >= 3: + left = stack.pop() + if r - left + 1 >= 3:solutions/3679/01.py (1)
17-17: Input mutation side effect.Setting
arrivals[idx] = 0mutates the caller's list. If this is intentional for the algorithm, consider documenting this behavior or working on a copy if the original array should be preserved.solutions/3685/01.py (1)
29-32: Consider binary search for finding first element > x.Since
sorted_numsis sorted, usingbisect.bisect_right(sorted_nums, x)would reduce this from O(n) to O(log n) per iteration, improving overall complexity.+from bisect import bisect_right + # Inside the loop: - ind = n - for i in range(n): - if sorted_nums[i] > x: - ind = i - break + ind = bisect_right(sorted_nums, x)solutions/3776/01.py (1)
43-43: Rename unused loop variable.The loop variable
idxis not used within the loop body.- for dist, idx, amount in positives: + for dist, _idx, amount in positives:explanations/3747/en.md (1)
62-70: Clean up the rambling commentary in the example walkthrough.This section contains stream-of-consciousness corrections ("Wait, let me reconsider", "Actually, the logic is:") that read like draft notes. Consider revising for clarity.
For example, simplify to:
For `n = 10`: - First digit is `1`: we can place digits 1 through (1-1)=0 freely, giving 0 choices - Second digit is `0`: encountering 0 means we can't form any zero-free numbers with this prefix - Return 9 (from step 2.2)explanations/3753/en.md (1)
9-11: Clarify the state count in complexity analysis.The
10^5state count isn't explained. For digit DP tracking (position, last_digit, second_last_digit, tight, has_started), the actual state space is approximatelyO(log n × 10 × 10 × 2 × 2)=O(log n × 400), which is smaller than10^5.Consider updating to:
- **Time Complexity:** O(log num2 × 10 × 10 × 2 × 2) - Digit DP with memoization - **Space Complexity:** O(log num2 × states) - Memoization cachescripts/update_problems_from_leetcode.py (2)
240-245: Narrow the exception type for file loading.Catching bare
Exceptioncan mask unexpected errors. Consider catching specific exceptions.try: with open(JSON_PATH, "r", encoding="utf-8") as f: return json.load(f) - except Exception as e: + except (OSError, json.JSONDecodeError) as e: print(f"Error reading JSON: {e}") return {}
248-264: Narrow the exception type for file saving.Same concern with bare
Exception. Also, thereturn Trueshould be in anelseblock for clarity.def save_json(data: Dict): """Save JSON file sorted by problem ID.""" try: # Sort by problem ID (convert key to int for proper numeric sorting) sorted_items = sorted( data.items(), key=lambda item: int(item[0]) if item[0].isdigit() else float("inf"), ) sorted_data = OrderedDict(sorted_items) # Write JSON (Prettier will format it via pre-commit hook) with open(JSON_PATH, "w", encoding="utf-8") as f: json.dump(sorted_data, f, ensure_ascii=False, indent=2) - return True - except Exception as e: + except OSError as e: print(f"Error saving JSON: {e}") return False + else: + return True
📜 Review details
Configuration used: CodeRabbit UI
Review profile: CHILL
Plan: Pro
📒 Files selected for processing (27)
.gitignore(1 hunks)explanations/3676/en.md(1 hunks)explanations/3679/en.md(1 hunks)explanations/3680/en.md(1 hunks)explanations/3685/en.md(1 hunks)explanations/3689/en.md(1 hunks)explanations/3747/en.md(1 hunks)explanations/3753/en.md(1 hunks)explanations/3769/en.md(1 hunks)explanations/3774/en.md(1 hunks)explanations/3775/en.md(1 hunks)explanations/3776/en.md(1 hunks)explanations/3777/en.md(1 hunks)requirements.txt(1 hunks)scripts/update_problems_from_leetcode.py(1 hunks)solutions/3676/01.py(1 hunks)solutions/3679/01.py(1 hunks)solutions/3680/01.py(1 hunks)solutions/3685/01.py(1 hunks)solutions/3689/01.py(1 hunks)solutions/3747/01.py(1 hunks)solutions/3753/01.py(1 hunks)solutions/3769/01.py(1 hunks)solutions/3774/01.py(1 hunks)solutions/3775/01.py(1 hunks)solutions/3776/01.py(1 hunks)solutions/3777/01.py(1 hunks)
🧰 Additional context used
🪛 LanguageTool
explanations/3753/en.md
[style] ~9-~9: As an alternative to the over-used intensifier ‘very’, consider replacing this phrase.
Context: ... Size:** 1 <= num1 <= num2 <= 10^15 - Very large range - Time Complexity: O(log num2...
(EN_WEAK_ADJECTIVE)
explanations/3747/en.md
[style] ~9-~9: As an alternative to the over-used intensifier ‘very’, consider replacing this phrase.
Context: ... - Input Size: 1 <= n <= 10^15 - Very large, can't iterate through all numbers - **...
(EN_WEAK_ADJECTIVE)
🪛 markdownlint-cli2 (0.18.1)
explanations/3753/en.md
87-87: Spaces inside emphasis markers
(MD037, no-space-in-emphasis)
88-88: Spaces inside emphasis markers
(MD037, no-space-in-emphasis)
🪛 Ruff (0.14.8)
solutions/3680/01.py
2-2: Undefined name List
(F821)
2-2: Undefined name List
(F821)
solutions/3679/01.py
2-2: Undefined name List
(F821)
solutions/3689/01.py
2-2: Undefined name List
(F821)
solutions/3777/01.py
18-18: Undefined name List
(F821)
18-18: Undefined name List
(F821)
18-18: Undefined name List
(F821)
scripts/update_problems_from_leetcode.py
243-243: Do not catch blind exception: Exception
(BLE001)
261-261: Consider moving this statement to an else block
(TRY300)
262-262: Do not catch blind exception: Exception
(BLE001)
solutions/3774/01.py
2-2: Undefined name List
(F821)
solutions/3776/01.py
2-2: Undefined name List
(F821)
43-43: Loop control variable idx not used within loop body
Rename unused idx to _idx
(B007)
solutions/3685/01.py
2-2: Undefined name List
(F821)
2-2: Undefined name List
(F821)
solutions/3676/01.py
2-2: Undefined name List
(F821)
9-9: Ambiguous variable name: l
(E741)
⏰ 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). (1)
- GitHub Check: Sourcery review
🔇 Additional comments (24)
requirements.txt (1)
1-2: Empty requirements file.The file contains only blank lines. If no dependencies are needed, consider removing this file or adding a comment explaining its purpose. Otherwise, this is fine as a placeholder.
.gitignore (1)
12-14: LGTM!Good additions for ignoring Python artifacts. Note that
__pycache__/on line 14 now covers all__pycache__directories recursively, makingscripts/__pycache__/on line 11 redundant—you could remove line 11 for cleanliness, but keeping both is harmless.explanations/3689/en.md (1)
1-65: LGTM!Well-structured explanation with clear problem decomposition, complexity analysis, and illustrative code snippets. The greedy insight that the entire array maximizes
max - minis correctly reasoned.solutions/3774/01.py (1)
3-6: LGTM!The sorting approach correctly identifies the k smallest and k largest elements. The logic is sound and efficient.
explanations/3775/en.md (1)
1-76: LGTM!The explanation is clear, well-structured, and provides a good walkthrough of the algorithm with a concrete example. The decomposition and complexity analysis are accurate.
explanations/3774/en.md (1)
1-65: LGTM!The explanation is well-structured with clear problem decomposition, accurate complexity analysis, and a correct worked example demonstrating the sorting approach.
solutions/3676/01.py (1)
6-17: Verify algorithm correctness for the bowl condition.The algorithm counts subarrays based on length and stack state, but the bowl condition requires
min(ends) > max(middle). The current logic:
- Pops
lwhennums[l] <= valand counts if length ≥ 3- Counts with stack top if length ≥ 3
This assumes intermediate elements are smaller than both endpoints due to the monotonic stack property, but the reasoning is subtle. Since this problem was noted as "accepted," the algorithm may be correct, but I recommend adding a comment explaining why the bowl property is guaranteed.
solutions/3775/01.py (2)
7-8: Consider case-insensitive vowel counting if input may contain uppercase.The vowel set only includes lowercase letters. If the input string can contain uppercase letters (e.g., "Cat AND Mice"), uppercase vowels won't be counted.
If the problem guarantees lowercase input, this is fine. Otherwise, consider:
- vowels = {'a', 'e', 'i', 'o', 'u'} - first_vowel_count = sum(1 for c in words[0] if c in vowels) + vowels = {'a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U'} + first_vowel_count = sum(1 for c in words[0] if c in vowels)Or use
c.lower() in vowelsfor the check.
1-18: LGTM!The implementation is clean and correctly follows the algorithm: split words, count vowels in the first word, reverse subsequent words with matching vowel count, and join the result.
solutions/3747/01.py (1)
1-23: LGTM! Clean digit-based combinatorial solution.The algorithm correctly counts zero-free numbers by:
- Counting all zero-free numbers with fewer digits using powers of 9
- Processing same-length numbers digit-by-digit, stopping on zero
- Adding 1 if
nitself is zero-freeThe O(log n) time and space complexity is optimal for this problem.
explanations/3776/en.md (1)
1-100: LGTM! Well-structured explanation.The documentation clearly explains the greedy approach with proper complexity analysis, code snippets, and a worked example. The circular distance calculations in the walkthrough are correct.
explanations/3680/en.md (1)
1-83: LGTM! Clear geometric scheduling explanation.The documentation effectively explains the polygon-based approach for generating round-robin schedules, with appropriate complexity analysis and worked examples for both odd and even cases.
solutions/3776/01.py (1)
10-19: Algorithm only handles one negative balance.The code finds only the first negative index and balances it. If the problem allows multiple negative balances, this solution would be incomplete. Please verify that the problem guarantees at most one negative balance, or extend the algorithm to handle multiple negatives iteratively.
solutions/3680/01.py (1)
3-37: LGTM! Geometric round-robin scheduling implementation.The algorithm correctly implements the polygon-based approach for generating a valid double round-robin schedule with proper handling of odd/even cases and distance-based match generation.
solutions/3753/01.py (2)
5-5: Potential edge case:num1 = 0would cause error.If
num1can be 0, thennum1 - 1 = -1, andstr(-1)produces"-1"which would causeint('-')to fail in_total_waviness_upto. Consider adding a guard or clarifying the expected constraints.def totalWaviness(self, num1: int, num2: int) -> int: + if num1 == 0: + return self._total_waviness_upto(num2) w1 = self._total_waviness_upto(num1 - 1) w2 = self._total_waviness_upto(num2) return w2 - w1
13-49: LGTM! Well-implemented digit DP with memoization.The digit DP correctly tracks:
- Position, tight constraint, and started flag for leading zeros
- Last two real digits (p1, p2) for peak/valley detection
- Returns (waviness, count) tuple to propagate contributions through all completions
The peak/valley condition on line 44 correctly identifies local maxima and minima.
explanations/3685/en.md (1)
1-89: LGTM!The explanation is well-structured with clear problem restatement, complexity analysis, and step-by-step walkthrough. The subset-sum DP approach with per-cap processing is correctly described.
explanations/3679/en.md (1)
1-73: LGTM!The sliding window explanation is clear with proper complexity analysis and well-illustrated examples showing the discard mechanism.
solutions/3777/01.py (2)
1-15: LGTM!The Fenwick Tree implementation is correct with proper 1-based indexing for point updates and prefix sum queries.
29-44: LGTM!The query processing logic correctly handles both operation types. The flip operation properly updates violation counts by leveraging the fact that flipping always toggles the equality relationship with neighbors.
explanations/3777/en.md (1)
1-74: LGTM!The explanation clearly describes the Fenwick Tree approach for tracking violations, with a well-illustrated example walkthrough that aligns with the implementation.
scripts/update_problems_from_leetcode.py (3)
292-299: Unconditional overwrite may discard local customizations.All existing entries are overwritten with API data (line 298), even if local JSON has customizations. If this is intentional, consider adding a comment. Otherwise, consider only updating specific fields or making this behavior configurable.
58-123: LGTM!The tag-to-category mapping is comprehensive with sensible priority ordering. The fallback to "Array & Hashing" is reasonable.
164-232: LGTM!Good implementation with proper rate limiting, pagination handling, and error recovery. The 2-second delay between batches is appropriate for avoiding rate limits.
| class Solution: | ||
| def bowlSubarrays(self, nums: List[int]) -> int: |
There was a problem hiding this comment.
Missing List import causes runtime error.
The type hint List[int] requires importing List from the typing module.
Apply this diff:
+from typing import List
+
+
class Solution:
def bowlSubarrays(self, nums: List[int]) -> int:🧰 Tools
🪛 Ruff (0.14.8)
2-2: Undefined name List
(F821)
🤖 Prompt for AI Agents
In solutions/3676/01.py around lines 1 to 2, the type hint uses List[int] but
List is not imported; add "from typing import List" at the top of the file
(above the class definition) so the List type is available and the
runtime/type-checking error is resolved.
| class Solution: | ||
| def minArrivalsToDiscard(self, arrivals: List[int], w: int, m: int) -> int: |
There was a problem hiding this comment.
Add missing List import.
The type hint List[int] requires importing List from typing. This will cause a NameError at runtime.
Apply this diff:
+from typing import List
+
+
class Solution:
def minArrivalsToDiscard(self, arrivals: List[int], w: int, m: int) -> int:🧰 Tools
🪛 Ruff (0.14.8)
2-2: Undefined name List
(F821)
🤖 Prompt for AI Agents
In solutions/3679/01.py around lines 1 to 2, the type hint uses 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 annotation resolves correctly and
avoids a NameError at runtime.
| class Solution: | ||
| def generateSchedule(self, n: int) -> List[List[int]]: |
There was a problem hiding this comment.
Add missing List import.
The type hint List[List[int]] requires importing List from typing. This will cause a NameError at runtime.
Apply this diff:
+from typing import List
+
+
class Solution:
def generateSchedule(self, n: int) -> List[List[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.
| class Solution: | |
| def generateSchedule(self, n: int) -> List[List[int]]: | |
| from typing import List | |
| class Solution: | |
| def generateSchedule(self, n: int) -> List[List[int]]: |
🧰 Tools
🪛 Ruff (0.14.8)
2-2: Undefined name List
(F821)
2-2: Undefined name List
(F821)
🤖 Prompt for AI Agents
In solutions/3680/01.py around lines 1 to 2, the type hint uses List but List is
not imported; add "from typing import List" at the top of the file (or include
List in an existing typing import) so the annotation List[List[int]] is defined
and avoids a NameError.
| class Solution: | ||
| def subsequenceSumAfterCapping(self, nums: List[int], k: int) -> List[bool]: |
There was a problem hiding this comment.
Add missing List import.
The type hints use List[int] and List[bool] without importing from typing. This will cause a NameError at runtime.
Apply this diff:
+from typing import List
+
+
class Solution:
def subsequenceSumAfterCapping(self, nums: List[int], k: int) -> List[bool]:📝 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.
| class Solution: | |
| def subsequenceSumAfterCapping(self, nums: List[int], k: int) -> List[bool]: | |
| from typing import List | |
| class Solution: | |
| def subsequenceSumAfterCapping(self, nums: List[int], k: int) -> List[bool]: |
🧰 Tools
🪛 Ruff (0.14.8)
2-2: Undefined name List
(F821)
2-2: Undefined name List
(F821)
🤖 Prompt for AI Agents
In solutions/3685/01.py around lines 1 to 2, the function signature uses type
hints List[int] and List[bool] but List is not imported; add "from typing import
List" at the top of the file so the type names are defined and the annotations
won't raise a NameError.
| class Solution: | ||
| def maxTotalValue(self, nums: List[int], k: int) -> int: | ||
| # The hint says to choose the whole subarray k times | ||
| # Value of whole subarray = max(nums) - min(nums) | ||
| max_val = max(nums) | ||
| min_val = min(nums) | ||
| return (max_val - min_val) * k |
There was a problem hiding this comment.
Missing import for List type hint.
List is undefined; this will raise a NameError if type hints are evaluated at runtime.
Add the import at the top of the file:
+from typing import List
+
+
class Solution:
def maxTotalValue(self, nums: List[int], k: int) -> int:Alternatively, for Python 3.9+, use the built-in list (lowercase):
def maxTotalValue(self, nums: list[int], k: int) -> int:🧰 Tools
🪛 Ruff (0.14.8)
2-2: Undefined name List
(F821)
🤖 Prompt for AI Agents
In solutions/3689/01.py around lines 1 to 7, the type hint uses List but List is
not imported, causing a NameError; fix by either adding "from typing import
List" at the top of the file or change the signature to use built-in generic
syntax (e.g., nums: list[int]) depending on project Python version, and ensure
any added import is placed before the class definition.
| class Solution: | ||
| def sortByReflection(self, nums: List[int]) -> List[int]: | ||
| def binary_reflection(n): | ||
| # Convert to binary, remove '0b' prefix, reverse, convert back to int | ||
| binary = bin(n)[2:] | ||
| # Convert to binary, reverse, convert back | ||
| binary = bin(n)[2:] # Remove '0b' prefix | ||
| reversed_binary = binary[::-1] | ||
| return int(reversed_binary, 2) | ||
|
|
||
| # Sort by binary reflection, then by original value if reflection is equal | ||
| res = sorted(nums, key=lambda x: (binary_reflection(x), x)) | ||
| return res | ||
|
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||
|
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||
| return sorted(nums, key=lambda x: (binary_reflection(x), x)) |
There was a problem hiding this comment.
Missing import for List type hint.
Same issue as solutions/3689/01.py—List is undefined.
Add the import:
+from typing import List
+
+
class Solution:
def sortByReflection(self, nums: List[int]) -> List[int]:The refactored logic returning sorted() directly is clean and correct.
🧰 Tools
🪛 Ruff (0.14.8)
2-2: Undefined name List
(F821)
2-2: Undefined name List
(F821)
🤖 Prompt for AI Agents
In solutions/3769/01.py around lines 1 to 9, the type hint List is undefined
causing a NameError; add the missing import "from typing import List" at the top
of the file (before the Solution class) so the List annotation is resolved,
leaving the rest of the function and its refactored sorted return unchanged.
| class Solution: | ||
| def absDifference(self, nums: List[int], k: int) -> int: |
There was a problem hiding this comment.
Missing List import causes runtime error.
The type hint List[int] requires importing List from the typing module.
Apply this diff:
+from typing import List
+
+
class Solution:
def absDifference(self, nums: List[int], k: int) -> int:🧰 Tools
🪛 Ruff (0.14.8)
2-2: Undefined name List
(F821)
🤖 Prompt for AI Agents
In solutions/3774/01.py around lines 1 to 2, the type hint uses List[int] but
List is not imported; add "from typing import List" at top of the file (or
replace List[int] with built-in list[int] for Python 3.9+) so the type
annotation resolves and runtime/type-checking errors are avoided.
| class Solution: | ||
| def minMoves(self, balance: List[int]) -> int: |
There was a problem hiding this comment.
Add missing List import.
The type hint List[int] requires importing List from typing. This will cause a NameError at runtime.
Apply this diff:
+from typing import List
+
+
class Solution:
def minMoves(self, balance: List[int]) -> int:🧰 Tools
🪛 Ruff (0.14.8)
2-2: Undefined name List
(F821)
🤖 Prompt for AI Agents
In solutions/3776/01.py around lines 1 to 2, the type hint uses List[int] but
List is not imported; add a top-level import "from typing import List" (or
include List in an existing typing import) so the type annotation is defined and
avoids a NameError at runtime.
| return s | ||
|
|
||
| class Solution: | ||
| def minDeletions(self, s: str, queries: List[List[int]]) -> List[int]: |
There was a problem hiding this comment.
Missing import for List type hint.
The static analysis correctly identifies that List is not imported, which will cause a NameError at runtime.
+from typing import List
+
class FenwickTree:📝 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.
| def minDeletions(self, s: str, queries: List[List[int]]) -> List[int]: | |
| from typing import List | |
| class FenwickTree: |
🧰 Tools
🪛 Ruff (0.14.8)
18-18: Undefined name List
(F821)
18-18: Undefined name List
(F821)
18-18: Undefined name List
(F821)
🤖 Prompt for AI Agents
In solutions/3777/01.py around line 18, the type hint uses List but List is not
imported; add the missing import by importing List (e.g., from typing import
List) at the top of the file or replace List with a built-in type annotation
(like list) to resolve the NameError and ensure type hints are valid.
romankurnovskii
deleted the
problems-3774-3775-3776-3777-3769-3753-3747-3705-3689-3685-3680-3679-3676
branch
2 participants
Summary
Added solutions and explanations for 12 LeetCode problems.
Accepted Solutions (7 problems):
Solutions with Explanations (5 problems):
Notes:
resas the result variable name as per repository standardsSummary by Sourcery
Add optimized solutions and detailed explanations for multiple recent LeetCode problems, and introduce a script to sync the local problem metadata with the LeetCode API.
New Features:
Enhancements:
Build:
Documentation:
Chores:
Summary by CodeRabbit
New Features
Documentation
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