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How to Solve Cousins in Binary Tree II Problem
Master the Cousins in Binary Tree II LeetCode problem with undetectable real-time assistance. Get instant solutions and explanations during your coding interviews.
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Start Free for WindowsMedium#2641
LeetCode ProblemCousins in Binary Tree II
Given the root of a binary tree, replace the value of each node in the tree with the sum of all its cousins' values. Two nodes of a binary tree are cousins if they have the same depth with different parents. Return the root of the modified tree. Note that the depth of a node is the number of edges in the path from the root node to it.
Hash TableTreeDepth-First SearchBreadth-First SearchBinary Tree
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Problem Breakdown
Understanding the Cousins in Binary Tree II Problem
Let's break down this LeetCode problem and understand what makes it challenging in interview settings.
Problem Statement
Given the root of a binary tree, replace the value of each node in the tree with the sum of all its cousins' values. Two nodes of a binary tree are cousins if they have the same depth with different parents. Return the root of the modified tree. Note that the depth of a node is the number of edges in the path from the root node to it.
MediumProblem #2641
LeetCodeCousins in Binary Tree II
Related Topics
Hash TableTreeDepth-First SearchBreadth-First SearchBinary Tree
How Phantom Code Helps
Get real-time assistance for Cousins in Binary Tree II problems during coding interviews. Phantom Code provides instant solutions and explanations.
Examples
# Example 1
Input
root = [5,4,9,1,10,null,7]
Output
[0,0,0,7,7,null,11]
# Example 2
Input
root = [3,1,2]
Output
[0,0,0]
Constraints
The number of nodes in the tree is in the range [1, 105].
1 <= Node.val <= 104
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Solve Cousins in Binary Tree II — Given the root of a binary tree, replace the value of each node in the tree with...
Here's the optimal approach using Hash Table:
def solve(input):
# Optimal O(n) solution
return result
Time: O(n) | Space: O(n)
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Frequently Asked Questions
Common questions about solving Cousins in Binary Tree II and using Phantom Code during coding interviews.
How does Phantom Code help me solve coding problems like Cousins in Binary Tree II during interviews?
Phantom Code generates complete solutions instantly with proper complexity analysis, letting you focus on explaining your approach and demonstrating problem-solving skills rather than getting stuck on implementation details during high-pressure situations.
What if the interviewer asks follow-up questions or modifications to problems like Cousins in Binary Tree II?
Phantom Code adapts in real-time. Screenshot the modified problem or use audio mode to capture the interviewer's follow-up, and get an updated solution within seconds — including edge cases and optimizations.
Can Phantom Code help me communicate my solution for problems like Cousins in Binary Tree II?
Yes. Phantom Code provides step-by-step approach explanations with 3 progressive thoughts, so you can walk through your solution naturally. It also provides time and space complexity analysis to discuss trade-offs.
How does Phantom Code assist with different programming languages for Cousins in Binary Tree II type problems?
Phantom Code supports 11 programming languages including Python, Java, C++, JavaScript, TypeScript, Go, Rust, Ruby, Swift, Kotlin, and C#. Set your preferred language and get idiomatic solutions.
What coding mistakes does Phantom Code help me avoid during Cousins in Binary Tree II interviews?
Phantom Code catches common mistakes like off-by-one errors, missing edge cases, incorrect base conditions, and suboptimal approaches. It provides clean, well-structured code that handles all edge cases.
Is Phantom Code detectable when solving problems like Cousins in Binary Tree II during live interviews?
No. Phantom Code runs as an invisible desktop overlay that doesn't appear in screen shares, recordings, or proctoring software. It works with Zoom, HackerRank, CodeSignal, CoderPad, and all major platforms.
How does Phantom Code help when I'm struggling with Cousins in Binary Tree II style questions under pressure?
The AI provides structured guidance: first the approach (what algorithm/data structure to use and why), then the implementation with clean code, and finally complexity analysis. This helps you think clearly even under pressure.
Does Phantom Code work for the coding platforms used in Cousins in Binary Tree II interviews?
Yes. Phantom Code works with all major coding platforms including LeetCode, HackerRank, CodeSignal, CoderPad, HackerEarth, and any browser-based coding environment.
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