Tree: Depth-First Search - Count Complete Tree Nodes
Given the following partial output of the countNodes function on a complete binary tree:
Output: 15
Which of the following could be the height of the tree?
Given the following partial output of the countNodes function on a complete binary tree: Output: 15 Which of the following could be the height of the tree?
hard🔄 Reverse Engineer Q9 of Q15
Step-by-Step Solution
Solution:
Step 1: Recall perfect tree node counts
Perfect tree with height h has 2^h - 1 nodes.Step 2: Check which height matches 15 nodes
2^4 - 1 = 15, so height = 4.Final Answer:
Option B -> Option BQuick Check:
15 nodes correspond to perfect tree height 4 [OK]
Quick Trick: Nodes = 2^h - 1 for perfect tree [OK]
Common Mistakes:
MISTAKES- Confusing height with node count
- Off-by-one in exponentiation
Trap Explanation:
PITFALL- Candidates often miscalculate node count for given height.
Interviewer Note:
CONTEXT- Tests ability to reverse engineer tree height from node count.
Master "Count Complete Tree Nodes" 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