BFS-1 Assignment Completed

[Hriday-A]

No description provided.

[super30admin]

Level Order Traversal in Binary tree (binary_tree_traversal.java)

Strengths:

1. Excellent that you provided two different approaches - BFS (iterative) and DFS (recursive), showing good understanding of multiple paradigms
2. The DFS approach demonstrates clever use of the level parameter to organize results by depth
3. Good comment explaining the reference semantics issue with result.get(level).add(root.val)
4. Clean separation between approaches with clear comments
5. Proper handling of edge cases (empty tree returns empty list)

Areas for Improvement:

1. In the DFS approach, consider using result.get(level).add(root.val) directly instead of the intermediate li variable - while your approach works, the direct method is more concise and equally clear
2. The BFS approach could benefit from a brief comment explaining why we capture size before the loop (to avoid processing nodes added during the current level)
3. Consider adding a brief explanation of when to prefer BFS vs DFS for this problem (BFS is more intuitive for level-order; DFS uses less memory for the queue but has call stack overhead)

Minor Optimization:
The DFS approach is already optimal. If you wanted to micro-optimize, you could pre-allocate the ArrayList capacity, but this would be negligible for this problem.

VERDICT: PASS

---

Scheduling Courses (course_schedule.java)

Strengths:

1. Correctly implements the topological sort (Kahn's algorithm) approach - a valid alternative to the DFS solution
2. Good use of early return optimization when all courses are processed
3. Clear comments explaining the logic
4. Efficient O(V+E) time and space complexity

Areas for Improvement:

1. Code formatting: The indentation is inconsistent, making the code harder to read. The closing brace of the class should be properly aligned.
2. Variable naming: count could be renamed to something more descriptive like processedCourses or coursesCompleted.
3. Redundant check: The check if(q.isEmpty()) return false; after the initial queue population is unnecessary because if all courses have indegree > 0, it means there's a cycle, but this is already handled by the final return false.
4. Consider using ArrayList initialization: When creating the adjacency list, you could initialize with new ArrayList<>() for each new key to avoid null checks later.

Overall, this is a solid solution that correctly solves the problem with good algorithmic approach.

VERDICT: PASS