Tree: Depth-First Search - Serialize and Deserialize Binary Tree
Consider the BFS-based serialization code. What is the serialized string output for an empty tree (root = None)?
Consider the BFS-based serialization code. What is the serialized string output for an empty tree (root = None)?
medium🧾 Code Trace Q4 of Q15
Step-by-Step Solution
Solution:
Step 1: Check base case
Input root is None, so the code returns an empty string immediately.Step 2: Confirm output
Empty tree serializes to empty string "" as per code.Final Answer:
Option D -> Option DQuick Check:
Empty tree serialization returns empty string [OK]
Quick Trick: Empty tree serializes to empty string [OK]
Common Mistakes:
MISTAKES- Returning 'X' or 'null' instead of empty string
- Assuming root.val exists for empty tree
Trap Explanation:
PITFALL- Candidates often assume a placeholder string for empty tree instead of empty string.
Interviewer Note:
CONTEXT- Tests handling of edge case empty input in serialization.
Master "Serialize and Deserialize Binary Tree" in Tree: Depth-First Search
Want More Practice?
15+ quiz questions · All difficulty levels · Free
Free Signup - Practice All QuestionsMore Tree: Depth-First Search Quizzes