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How to Solve Shortest Path with Alternating Colors Problem
Master the Shortest Path with Alternating Colors LeetCode problem with undetectable real-time assistance. Get instant solutions and explanations during your coding interviews.
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Start Free for WindowsMedium#1129
LeetCode ProblemShortest Path with Alternating Colors
You are given an integer n, the number of nodes in a directed graph where the nodes are labeled from 0 to n - 1. Each edge is red or blue in this graph, and there could be self-edges and parallel edges. You are given two arrays redEdges and blueEdges where: Return an array answer of length n, where each answer[x] is the length of the shortest path from node 0 to node x such that the edge colors alternate along the path, or -1 if such a path does not exist.
Breadth-First SearchGraph
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Problem Breakdown
Understanding the Shortest Path with Alternating Colors Problem
Let's break down this LeetCode problem and understand what makes it challenging in interview settings.
Problem Statement
You are given an integer n, the number of nodes in a directed graph where the nodes are labeled from 0 to n - 1. Each edge is red or blue in this graph, and there could be self-edges and parallel edges. You are given two arrays redEdges and blueEdges where: Return an array answer of length n, where each answer[x] is the length of the shortest path from node 0 to node x such that the edge colors alternate along the path, or -1 if such a path does not exist.
MediumProblem #1129
LeetCodeShortest Path with Alternating Colors
Related Topics
Breadth-First SearchGraph
How Phantom Code Helps
Get real-time assistance for Shortest Path with Alternating Colors problems during coding interviews. Phantom Code provides instant solutions and explanations.
Examples
# Example 1
Input
n = 3, redEdges = [[0,1],[1,2]], blueEdges = []
Output
[0,1,-1]
# Example 2
Input
n = 3, redEdges = [[0,1]], blueEdges = [[2,1]]
Output
[0,1,-1]
Constraints
1 <= n <= 100
0 <= redEdges.length, blueEdges.length <= 400
redEdges[i].length == blueEdges[j].length == 2
0 <= ai, bi, uj, vj < n
How Phantom Code Helps with LeetCode Problems
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Solve Shortest Path with Alternating Colors — You are given an integer n, the number of nodes in a directed graph where the no...
Here's the optimal approach using Breadth-First Search:
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 Shortest Path with Alternating Colors and using Phantom Code during coding interviews.
How does Phantom Code help me solve coding problems like Shortest Path with Alternating Colors 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 Shortest Path with Alternating Colors?
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 Shortest Path with Alternating Colors?
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 Shortest Path with Alternating Colors 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 Shortest Path with Alternating Colors 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 Shortest Path with Alternating Colors 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 Shortest Path with Alternating Colors 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 Shortest Path with Alternating Colors 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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