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How to Solve Reconstruct a 2-Row Binary Matrix Problem
Master the Reconstruct a 2-Row Binary Matrix LeetCode problem with undetectable real-time assistance. Get instant solutions and explanations during your coding interviews.
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Start Free for WindowsMedium#1253
LeetCode ProblemReconstruct a 2-Row Binary Matrix
Given the following details of a matrix with n columns and 2 rows : Your task is to reconstruct the matrix with upper, lower and colsum. Return it as a 2-D integer array. If there are more than one valid solution, any of them will be accepted. If no valid solution exists, return an empty 2-D array.
ArrayGreedyMatrix
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Problem Breakdown
Understanding the Reconstruct a 2-Row Binary Matrix Problem
Let's break down this LeetCode problem and understand what makes it challenging in interview settings.
Problem Statement
Given the following details of a matrix with n columns and 2 rows : Your task is to reconstruct the matrix with upper, lower and colsum. Return it as a 2-D integer array. If there are more than one valid solution, any of them will be accepted. If no valid solution exists, return an empty 2-D array.
MediumProblem #1253
LeetCodeReconstruct a 2-Row Binary Matrix
Related Topics
ArrayGreedyMatrix
How Phantom Code Helps
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Examples
# Example 1
Input
upper = 2, lower = 1, colsum = [1,1,1]
Output
[[1,1,0],[0,0,1]]
# Example 2
Input
upper = 2, lower = 3, colsum = [2,2,1,1]
Output
[]
# Example 3
Input
upper = 5, lower = 5, colsum = [2,1,2,0,1,0,1,2,0,1]
Output
[[1,1,1,0,1,0,0,1,0,0],[1,0,1,0,0,0,1,1,0,1]]
Constraints
1 <= colsum.length <= 10^5
0 <= upper, lower <= colsum.length
0 <= colsum[i] <= 2
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Solve Reconstruct a 2-Row Binary Matrix — Given the following details of a matrix with n columns and 2 rows : Your task is...
Here's the optimal approach using Array:
def solve(input):
# Optimal O(n) solution
return result
Time: O(n) | Space: O(n)
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Frequently Asked Questions
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How does Phantom Code help me solve coding problems like Reconstruct a 2-Row Binary Matrix 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 Reconstruct a 2-Row Binary Matrix?
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 Reconstruct a 2-Row Binary Matrix?
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 Reconstruct a 2-Row Binary Matrix 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 Reconstruct a 2-Row Binary Matrix 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 Reconstruct a 2-Row Binary Matrix during live interviews?
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How does Phantom Code help when I'm struggling with Reconstruct a 2-Row Binary Matrix 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.
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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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