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How to Solve Validate Binary Tree Nodes Problem
Master the Validate Binary Tree Nodes LeetCode problem with undetectable real-time assistance. Get instant solutions and explanations during your coding interviews.
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Start Free for WindowsMedium#1361
LeetCode ProblemValidate Binary Tree Nodes
You have n binary tree nodes numbered from 0 to n - 1 where node i has two children leftChild[i] and rightChild[i], return true if and only if all the given nodes form exactly one valid binary tree. If node i has no left child then leftChild[i] will equal -1, similarly for the right child. Note that the nodes have no values and that we only use the node numbers in this problem.
TreeDepth-First SearchBreadth-First SearchUnion FindGraphBinary Tree
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Problem Breakdown
Understanding the Validate Binary Tree Nodes Problem
Let's break down this LeetCode problem and understand what makes it challenging in interview settings.
Problem Statement
You have n binary tree nodes numbered from 0 to n - 1 where node i has two children leftChild[i] and rightChild[i], return true if and only if all the given nodes form exactly one valid binary tree. If node i has no left child then leftChild[i] will equal -1, similarly for the right child. Note that the nodes have no values and that we only use the node numbers in this problem.
MediumProblem #1361
LeetCodeValidate Binary Tree Nodes
Related Topics
TreeDepth-First SearchBreadth-First SearchUnion FindGraphBinary Tree
How Phantom Code Helps
Get real-time assistance for Validate Binary Tree Nodes problems during coding interviews. Phantom Code provides instant solutions and explanations.
Examples
# Example 1
Input
n = 4, leftChild = [1,-1,3,-1], rightChild = [2,-1,-1,-1]
Output
true
# Example 2
Input
n = 4, leftChild = [1,-1,3,-1], rightChild = [2,3,-1,-1]
Output
false
# Example 3
Input
n = 2, leftChild = [1,0], rightChild = [-1,-1]
Output
false
Constraints
n == leftChild.length == rightChild.length
1 <= n <= 104
-1 <= leftChild[i], rightChild[i] <= n - 1
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Solve Validate Binary Tree Nodes — You have n binary tree nodes numbered from 0 to n - 1 where node i has two child...
Here's the optimal approach using Tree:
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 Validate Binary Tree Nodes and using Phantom Code during coding interviews.
How does Phantom Code help me solve coding problems like Validate Binary Tree Nodes 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 Validate Binary Tree Nodes?
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 Validate Binary Tree Nodes?
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 Validate Binary Tree Nodes 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 Validate Binary Tree Nodes 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 Validate Binary Tree Nodes 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 Validate Binary Tree Nodes 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 Validate Binary Tree Nodes 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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