[Solved] In the following modified code snippet for the Bi... In the following modified code snippet for the Binary Tree Cameras problem, which line contains the subtle bug that causes incorrect camera count? | Tree: Depth-First Search

Tree: Depth-First Search - Binary Tree Cameras

In the following modified code snippet for the Binary Tree Cameras problem, which line contains the subtle bug that causes incorrect camera count? ```python if left == NOT_COVERED or right == NOT_COVERED: self.cameras += 1 return COVERED_NO_CAM # <-- suspect line ```

ANot checking if root is uncovered after traversal

BReturning COVERED_NO_CAM instead of HAS_CAM after placing a camera

CReturning NOT_COVERED for null nodes instead of COVERED_NO_CAM

DIncrementing cameras multiple times for the same node

Step-by-Step Solution

Solution:

Step 1: Identify expected return after placing camera
After placing a camera, node must return HAS_CAM to indicate coverage.
Step 2: Check code line
Code returns COVERED_NO_CAM instead, causing parent to misinterpret coverage.
Final Answer:
Option B -> Option B
Quick Check:
Incorrect return state leads to missed coverage and wrong camera count [OK]

Quick Trick: Placed camera must return HAS_CAM state [OK]

Common Mistakes:

MISTAKES

Returning wrong coverage state after camera placement

Trap Explanation:

PITFALL

Returning COVERED_NO_CAM looks plausible but breaks coverage logic subtly.

Interviewer Note:

CONTEXT

Tests candidate's understanding of coverage state semantics

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More Tree: Depth-First Search Quizzes

In the following modified code snippet for the Binary Tree Cameras problem, which line contains the subtle bug that causes incorrect camera count?

Step 1: Identify expected return after placing camera

Step 2: Check code line

Final Answer:

Quick Check:

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