Phantom Code AIPhantom Code AI
FeaturesEarn with UsMy WorkspacePricing
FeaturesEarn with UsMy WorkspacePricing
Phantom Code AIPhantom Code AI
FeaturesEarn with UsMy WorkspacePricing
FeaturesEarn with UsMy WorkspacePricing
HomeLeetCode ProblemsKth Smallest Path XOR Sum
Used by thousands of developers who passed their interviews

How to Solve Kth Smallest Path XOR Sum Problem

Master the Kth Smallest Path XOR Sum LeetCode problem with undetectable real-time assistance. Get instant solutions and explanations during your coding interviews.

Phantom Code AI generates complete solutions and debugging hints that you can use while explaining your approach, so you stay calm and in control.

undetectable
real-time
works on major platforms
Start Free
Hard#3590
LeetCode Problem

Kth Smallest Path XOR Sum

You are given an undirected tree rooted at node 0 with n nodes numbered from 0 to n - 1. Each node i has an integer value vals[i], and its parent is given by par[i]. The path XOR sum from the root to a node u is defined as the bitwise XOR of all vals[i] for nodes i on the path from the root node to node u, inclusive. You are given a 2D integer array queries, where queries[j] = [uj, kj]. For each query, find the kjth smallest distinct path XOR sum among all nodes in the subtree rooted at uj. If there are fewer than kj distinct path XOR sums in that subtree, the answer is -1. Return an integer array where the jth element is the answer to the jth query. In a rooted tree, the subtree of a node v includes v and all nodes whose path to the root passes through v, that is, v and its descendants.

ArrayTreeDepth-First SearchOrdered Set

Phantom Code AI will help you solve this problem in real-time during your interview

Get instant solutions, explanations, and code generation
Problem Breakdown

Understanding the Kth Smallest Path XOR Sum Problem

Let's break down this LeetCode problem and understand what makes it challenging in interview settings.

Problem Statement

You are given an undirected tree rooted at node 0 with n nodes numbered from 0 to n - 1. Each node i has an integer value vals[i], and its parent is given by par[i]. The path XOR sum from the root to a node u is defined as the bitwise XOR of all vals[i] for nodes i on the path from the root node to node u, inclusive. You are given a 2D integer array queries, where queries[j] = [uj, kj]. For each query, find the kjth smallest distinct path XOR sum among all nodes in the subtree rooted at uj. If there are fewer than kj distinct path XOR sums in that subtree, the answer is -1. Return an integer array where the jth element is the answer to the jth query. In a rooted tree, the subtree of a node v includes v and all nodes whose path to the root passes through v, that is, v and its descendants.

HardProblem #3590
LeetCode

Kth Smallest Path XOR Sum

Related Topics

ArrayTreeDepth-First SearchOrdered Set

How Phantom Code AI Helps

Get real-time assistance for Kth Smallest Path XOR Sum problems during coding interviews. Phantom Code AI provides instant solutions and explanations.

Examples

# Example 1

Input
par = [-1,0,0], vals = [1,1,1], queries = [[0,1],[0,2],[0,3]]
Output
[0,1,-1]

# Example 2

Input
par = [-1,0,1], vals = [5,2,7], queries = [[0,1],[1,2],[1,3],[2,1]]
Output
[0,7,-1,0]

Constraints

1 <= n == vals.length <= 5 * 104
0 <= vals[i] <= 105
par.length == n
par[0] == -1
0 <= par[i] < n for i in [1, n - 1]
1 <= queries.length <= 5 * 104
queries[j] == [uj, kj]
0 <= uj < n
1 <= kj <= n
The input is generated such that the parent array par represents a valid tree.

How Phantom Code AI Helps with LeetCode Problems

Reinforce undetectability, platform compatibility, and real-time assistance to remove any doubt.

1000+
developers use Phantom Code AI
and growing every day
95%
success rate
of users pass their interviews
100%
undetectable
native desktop architecture
Real-time
assistance
instant solutions during interviews

See Phantom Code AI in Action

Watch how Phantom Code AI helps solve LeetCode problems during live interviews

Phantom Code AI
Start Interview
⌘I
Online Round
⌘O
Hide⌘B
Interview
Listening
Think

Solve Kth Smallest Path XOR Sum — You are given an undirected tree rooted at node 0 with n nodes numbered from 0 t...

Here's the optimal approach using Array:

def solve(input):
# Optimal O(n) solution
return result

Time: O(n)  |  Space: O(n)

Start Over ⌘G
Think & Crack ⌘↵

Undetectability Checklist

Run compatibility test before interviews
Use recommended Zoom version settings
Enable advanced screen capture options
Verify native desktop architecture
Test with screen recording software

Platform Compatibility

Zoom
Supported
Google Meet
Supported
HackerRank
Supported
CodeSignal
Supported
CoderPad
Supported
Teams
Supported

User results and traction

Thousands of developers use Phantom Code AI. Social proof signals that this approach helps real candidates land offers across a range of companies.

Undetectability and technical details

Our native desktop architecture avoids common detection vectors used by browser extensions. We provide a clear checklist so you can run basic checks and confirm the app will be invisible.

Platform compatibility and limitations

We work with Zoom, HackerRank, CodeSignal, CoderPad and other web-based platforms. Check the compatibility note and request a browser link if a specific desktop app is unsupported.

Frequently Asked Questions

Common questions about solving Kth Smallest Path XOR Sum and using Phantom Code AI during coding interviews.

How does Phantom Code AI help me solve coding problems like Kth Smallest Path XOR Sum during interviews?
Phantom Code AI 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 Kth Smallest Path XOR Sum?
Phantom Code AI 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 AI help me communicate my solution for problems like Kth Smallest Path XOR Sum?
Yes. Phantom Code AI 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 AI assist with different programming languages for Kth Smallest Path XOR Sum type problems?
Phantom Code AI 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 AI help me avoid during Kth Smallest Path XOR Sum interviews?
Phantom Code AI 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 AI detectable when solving problems like Kth Smallest Path XOR Sum during live interviews?
No. Phantom Code AI 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 AI help when I'm struggling with Kth Smallest Path XOR Sum 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 AI work for the coding platforms used in Kth Smallest Path XOR Sum interviews?
Yes. Phantom Code AI works with all major coding platforms including LeetCode, HackerRank, CodeSignal, CoderPad, HackerEarth, and any browser-based coding environment.
Phantom Code AI

20+ Stealth Features. Zero Detection Cases.

The only AI interview tool with an undetectable desktop overlay, real-time audio listening, and personalized AI responses.

Start Free
Phantom Code AIPhantom Code AI
Phantom Code AI is an undetectable desktop application to help you pass your Leetcode interviews.
All systems online
Download

Legal

Refund PolicyTerms of ServiceCancellation PolicyPrivacy Policy

Pages

Contact SupportHelp CenterInstant SupportFAQBlogFeaturesInterview CopilotAI Mock InterviewCoding CopilotInterview QuestionsPricingBest AI Interview Assistants 2026FeedbackLeetcode ProblemsLoginCreate Account

Compare

All 29 comparisons →Why switch (29 alternatives) →Interview Coder AlternativeFinal Round AI AlternativeUltraCode AI AlternativeParakeet AI AlternativeAI Apply AlternativeCoderRank AlternativeInterviewing.io AlternativeShadeCoder Alternative

Resources

Salary GuideResume TemplatesWhat Is Phantom Code AIIs Phantom Code AI Detectable?Use Phantom Code AI in HackerRankvs LeetCode PremiumFor European EngineersFor FAANG Interview PrepPost-Layoff ComebackIndia Pricing (INR)

Interview Types

Coding InterviewSystem Design InterviewDSA InterviewLeetCode InterviewAlgorithms InterviewData Structure InterviewSQL InterviewOnline Assessment

Alternatives — why engineers switch

See all 29 →
Interview CoderFinal Round AIParakeet AILockedIn AIUltraCode AIShadeCoderSensei AIVerve AICluelyChatGPTBeyz AIInterview SidekickYoodliAlgoMonsterCoderRankExponentFormationInterviewing.ioInterview CakeBig InterviewInterview KickstartPrampScalerAI ApplyCareerflowJobscanKickresumeTeal HQHireVue

© 2026 Phantom Code AI. All rights reserved.