[Solved] Consider the following Python code implementing the Morris Preorder Traversal approach to... Given the binary tree: 1 / \ 2 3 What is the final value of the variable total returned by sumNumbers? | Tree: Depth-First Search

Tree: Depth-First Search - Sum Root to Leaf Numbers

Consider the following Python code implementing the Morris Preorder Traversal approach to sum root-to-leaf numbers. Given the binary tree: 1 / \ 2 3 What is the final value of the variable total returned by sumNumbers?

A5

B15

C25

D26

Step-by-Step Solution

Step 1: Trace path 1->2
current_number accumulates 1 then 12; leaf node 2 adds 12 to total.
Step 2: Trace path 1->3
current_number resets to 1, then accumulates 13; leaf node 3 adds 13 to total. Total = 12 + 13 = 25.
Step 3: Check for off-by-one or missed increments
Integer division after visiting left subtree correctly adjusts current_number; no extra addition occurs.
Final Answer:
Option C -> Option C
Quick Check:
Sum of 12 and 13 is 25, matching code behavior [OK]

Quick Trick: Trace current_number updates carefully at each node [OK]

Common Mistakes:

MISTAKES

Off-by-one in current_number division
Adding non-leaf nodes to total

Trap Explanation:

PITFALL

Integer division of current_number after visiting left subtree can cause subtle off-by-one errors if mishandled.

Interviewer Note:

CONTEXT

Tests candidate's ability to mentally execute Morris traversal and track variable state.

Master "Sum Root to Leaf Numbers" in Tree: Depth-First Search

3 interactive learning modes - each teaches the same concept differently

Try It Solution Trace

More Tree: Depth-First Search Quizzes

Given the binary tree: 1 / \ 2 3 What is the final value of the variable total returned by sumNumbers?

Step 1: Trace path 1->2

Step 2: Trace path 1->3

Step 3: Check for off-by-one or missed increments

Final Answer:

Quick Check:

Want More Practice?