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How to Solve Minimum Time to Collect All Apples in a Tree Problem
Master the Minimum Time to Collect All Apples in a Tree LeetCode problem with undetectable real-time assistance. Get instant solutions and explanations during your coding interviews.
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Start Free for WindowsMedium#1443
LeetCode ProblemMinimum Time to Collect All Apples in a Tree
Given an undirected tree consisting of n vertices numbered from 0 to n-1, which has some apples in their vertices. You spend 1 second to walk over one edge of the tree. Return the minimum time in seconds you have to spend to collect all apples in the tree, starting at vertex 0 and coming back to this vertex. The edges of the undirected tree are given in the array edges, where edges[i] = [ai, bi] means that exists an edge connecting the vertices ai and bi. Additionally, there is a boolean array hasApple, where hasApple[i] = true means that vertex i has an apple; otherwise, it does not have any apple.
Hash TableTreeDepth-First SearchBreadth-First Search
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Problem Breakdown
Understanding the Minimum Time to Collect All Apples in a Tree Problem
Let's break down this LeetCode problem and understand what makes it challenging in interview settings.
Problem Statement
Given an undirected tree consisting of n vertices numbered from 0 to n-1, which has some apples in their vertices. You spend 1 second to walk over one edge of the tree. Return the minimum time in seconds you have to spend to collect all apples in the tree, starting at vertex 0 and coming back to this vertex. The edges of the undirected tree are given in the array edges, where edges[i] = [ai, bi] means that exists an edge connecting the vertices ai and bi. Additionally, there is a boolean array hasApple, where hasApple[i] = true means that vertex i has an apple; otherwise, it does not have any apple.
MediumProblem #1443
LeetCodeMinimum Time to Collect All Apples in a Tree
Related Topics
Hash TableTreeDepth-First SearchBreadth-First Search
How Phantom Code Helps
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Examples
# Example 1
Input
n = 7, edges = [[0,1],[0,2],[1,4],[1,5],[2,3],[2,6]], hasApple = [false,false,true,false,true,true,false]
Output
8
# Example 2
Input
n = 7, edges = [[0,1],[0,2],[1,4],[1,5],[2,3],[2,6]], hasApple = [false,false,true,false,false,true,false]
Output
6
# Example 3
Input
n = 7, edges = [[0,1],[0,2],[1,4],[1,5],[2,3],[2,6]], hasApple = [false,false,false,false,false,false,false]
Output
0
Constraints
1 <= n <= 105
edges.length == n - 1
edges[i].length == 2
0 <= ai < bi <= n - 1
hasApple.length == n
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Solve Minimum Time to Collect All Apples in a Tree — Given an undirected tree consisting of n vertices numbered from 0 to n-1, which ...
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Frequently Asked Questions
Common questions about solving Minimum Time to Collect All Apples in a Tree and using Phantom Code during coding interviews.
How does Phantom Code help me solve coding problems like Minimum Time to Collect All Apples in a 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 Minimum Time to Collect All Apples in a 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 Minimum Time to Collect All Apples in a 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 Minimum Time to Collect All Apples in a 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 Minimum Time to Collect All Apples in a 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 Minimum Time to Collect All Apples in a 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 Minimum Time to Collect All Apples in a 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 Minimum Time to Collect All Apples in a 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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