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Use PracHub's coding console to write, test, and debug your solutions in Python or JavaScript. View hints, test against sample inputs, and compare with official solutions.

What difficulty level is this coding question?

This is a medium difficulty Coding & Algorithms question, commonly asked during Technical Screen rounds at Meta.

What role is this question designed for?

This question is commonly asked for Software Engineer candidates at Meta during technical interviews.

Validate near-palindrome and course prerequisite feasibility

Quick Overview

These problems evaluate string-processing and graph-theoretic competencies, testing algorithmic reasoning about near-palindrome validation with edge-case handling and course-prerequisite feasibility via cycle and ordering concepts, and are commonly asked to assess correctness, efficiency, and robustness under input constraints.

Company: Meta

Role: Software Engineer

Category: Coding & Algorithms

Difficulty: medium

Interview Round: Technical Screen

## Coding round (40 minutes): two problems You do **not** need to run code, but you should: - Explain your approach clearly. - Walk through the logic on examples. - Propose test cases and edge cases. ### Problem 1: Near-palindrome after deleting at most one character Given a string `s` containing lowercase English letters, determine whether `s` can become a palindrome after deleting **at most one** character. - **Input:** `s` - **Output:** `true` if `s` is already a palindrome or can be made into one by deleting at most one character; otherwise `false`. - **Constraints (typical):** `1 <= len(s) <= 1e5` ### Problem 2: Can all courses be completed? You are given: - An integer `n` representing courses labeled `0..n-1` - A list `prerequisites`, where each pair `[a, b]` means you must complete course `b` **before** course `a`. Determine whether it is possible to finish all courses. - **Input:** `n`, `prerequisites` - **Output:** `true` if there exists an ordering of all courses that satisfies prerequisites; otherwise `false`. - **Constraints (typical):** `1 <= n <= 1e5`, `0 <= len(prerequisites) <= 2e5`

Quick Answer: These problems evaluate string-processing and graph-theoretic competencies, testing algorithmic reasoning about near-palindrome validation with edge-case handling and course-prerequisite feasibility via cycle and ordering concepts, and are commonly asked to assess correctness, efficiency, and robustness under input constraints.

Near Palindrome With One Deletion

Return whether s is a palindrome after deleting at most one character.

Constraints

Inputs are Python literals matching the function signature.
Return a deterministic exact-match value.

Examples

Input: ('aba',)

Expected Output: True

Explanation: Already palindrome.

Input: ('abca',)

Expected Output: True

Explanation: Delete b or c.

Hints

Clarify edge cases before coding.
Keep the return value deterministic.

Course Prerequisite Feasibility

Return whether all courses can be completed under prerequisite constraints.

Constraints

Inputs are Python literals matching the function signature.
Return a deterministic exact-match value.

Examples

Input: (2, [[1,0]])

Expected Output: True

Explanation: Acyclic prerequisites.

Input: (2, [[1,0],[0,1]])

Expected Output: False

Explanation: Cycle prevents completion.

Hints

Clarify edge cases before coding.
Keep the return value deterministic.

Quick Overview