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How to Solve Parallel Courses III Problem

Master the Parallel Courses III LeetCode problem with undetectable real-time assistance. Get instant solutions and explanations during your coding interviews.

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Hard#2050

LeetCode Problem

Parallel Courses III

You are given an integer n, which indicates that there are n courses labeled from 1 to n. You are also given a 2D integer array relations where relations[j] = [prevCoursej, nextCoursej] denotes that course prevCoursej has to be completed before course nextCoursej (prerequisite relationship). Furthermore, you are given a 0-indexed integer array time where time[i] denotes how many months it takes to complete the (i+1)th course. You must find the minimum number of months needed to complete all the courses following these rules: Return the minimum number of months needed to complete all the courses. Note: The test cases are generated such that it is possible to complete every course (i.e., the graph is a directed acyclic graph).

ArrayDynamic ProgrammingGraphTopological Sort

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Problem Breakdown

Understanding the Parallel Courses III Problem

Let's break down this LeetCode problem and understand what makes it challenging in interview settings.

Problem Statement

HardProblem #2050

LeetCode

Parallel Courses III

How Phantom Code Helps

Get real-time assistance for Parallel Courses III problems during coding interviews. Phantom Code provides instant solutions and explanations.

Examples

# Example 1

Input

n = 3, relations = [[1,3],[2,3]], time = [3,2,5]

Output

# Example 2

Input

n = 5, relations = [[1,5],[2,5],[3,5],[3,4],[4,5]], time = [1,2,3,4,5]

Output

Constraints

1 <= n <= 5 * 104

0 <= relations.length <= min(n * (n - 1) / 2, 5 * 104)

relations[j].length == 2

1 <= prevCoursej, nextCoursej <= n

prevCoursej != nextCoursej

All the pairs [prevCoursej, nextCoursej] are unique.

time.length == n

1 <= time[i] <= 104

The given graph is a directed acyclic graph.

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Solve Parallel Courses III — You are given an integer n, which indicates that there are n courses labeled fro...

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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Undetectability Checklist

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Undetectability and technical details

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Frequently Asked Questions

Common questions about solving Parallel Courses III and using Phantom Code during coding interviews.

How does Phantom Code help me solve coding problems like Parallel Courses III 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 Parallel Courses III?

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 Parallel Courses III?

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 Parallel Courses III 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 Parallel Courses III 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 Parallel Courses III 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 Parallel Courses III 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 Parallel Courses III 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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