BFS-1

[hiteshmadapathi]

No description provided.

[super30admin]

Level Order Traversal in Binary tree (Problem1.py)

Strengths:

1. Correct implementation of BFS-based level order traversal
2. Proper handling of all edge cases (empty tree, single node)
3. Clean and readable code structure
4. Good use of collections.deque for efficient queue operations
5. Thoughtful comments explaining complexity analysis
6. Bonus: Provided an alternative DFS solution showing comprehensive understanding

Areas for Improvement:

1. The space complexity comment "O(n/2)" could be more precisely stated as O(n) since we use asymptotic notation
2. Consider adding type hints for better code documentation
3. The DFS solution is correct but could benefit from being in a separate method or class to avoid confusion

Overall, this is a solid solution that demonstrates good understanding of the BFS approach to tree traversal.

VERDICT: PASS

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Scheduling Courses (Problem2.py)

Strengths:

1. Clear and well-documented code with time/space complexity comments
2. Correct use of BFS-based topological sort (Kahn's algorithm)
3. Proper handling of edge cases (empty prerequisites, all courses independent, cyclic graphs)
4. Good variable naming (hmap, indegree, q) that makes the code readable
5. Efficient use of deque for O(1) queue operations

Areas for Improvement:

1. The count variable is incremented in two places (initial loop and when indegree becomes 0), which is correct but slightly redundant. You could simplify by only incrementing when adding to queue initially.
2. The early return if count == numCourses inside the while loop is good but could be moved outside the inner loop for slightly better readability.
3. Consider using defaultdict(list) from collections instead of manual dictionary initialization for cleaner code.
4. The condition if curr in hmap and len(hmap[curr])>0 can be simplified to just checking if curr in hmap since an empty list is falsy.

Time Complexity: O(V + E) - Same as reference solution ✓
Space Complexity: O(V + E) - Same as reference solution ✓

VERDICT: PASS