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How to Solve Second Minimum Node In a Binary Tree Problem
Master the Second Minimum Node In a Binary Tree LeetCode problem with undetectable real-time assistance. Get instant solutions and explanations during your coding interviews.
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LeetCode ProblemSecond Minimum Node In a Binary Tree
Given a non-empty special binary tree consisting of nodes with the non-negative value, where each node in this tree has exactly two or zero sub-node. If the node has two sub-nodes, then this node's value is the smaller value among its two sub-nodes. More formally, the property root.val = min(root.left.val, root.right.val) always holds. Given such a binary tree, you need to output the second minimum value in the set made of all the nodes' value in the whole tree. If no such second minimum value exists, output -1 instead.
TreeDepth-First SearchBinary Tree
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Problem Breakdown
Understanding the Second Minimum Node In a Binary Tree Problem
Let's break down this LeetCode problem and understand what makes it challenging in interview settings.
Problem Statement
Given a non-empty special binary tree consisting of nodes with the non-negative value, where each node in this tree has exactly two or zero sub-node. If the node has two sub-nodes, then this node's value is the smaller value among its two sub-nodes. More formally, the property root.val = min(root.left.val, root.right.val) always holds. Given such a binary tree, you need to output the second minimum value in the set made of all the nodes' value in the whole tree. If no such second minimum value exists, output -1 instead.
EasyProblem #671
LeetCodeSecond Minimum Node In a Binary Tree
Related Topics
TreeDepth-First SearchBinary Tree
How Phantom Code Helps
Get real-time assistance for Second Minimum Node In a Binary Tree problems during coding interviews. Phantom Code provides instant solutions and explanations.
Examples
# Example 1
Input
root = [2,2,5,null,null,5,7]
Output
5
# Example 2
Input
root = [2,2,2]
Output
-1
Constraints
The number of nodes in the tree is in the range [1, 25].
1 <= Node.val <= 231 - 1
root.val == min(root.left.val, root.right.val) for each internal node of the tree.
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Solve Second Minimum Node In a Binary Tree — Given a non-empty special binary tree consisting of nodes with the non-negative ...
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def solve(input):
# Optimal O(n) solution
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Frequently Asked Questions
Common questions about solving Second Minimum Node In a Binary Tree and using Phantom Code during coding interviews.
How does Phantom Code help me solve coding problems like Second Minimum Node In a Binary Tree 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 Second Minimum Node In a Binary Tree?
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 Second Minimum Node In a Binary Tree?
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 Second Minimum Node In a Binary Tree 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 Second Minimum Node In a Binary Tree 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 Second Minimum Node In a Binary Tree 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 Second Minimum Node In a Binary Tree 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 Second Minimum Node In a Binary Tree 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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