← JavaScript Coding

Word Ladder

hardblind-75dsagraphsbfs
Asked at
Cloudflare
Datadog
Netflix
Stripe
Vercel
Cloudflare, Datadog, Netflix, Stripe, Vercel

Problem statement

Implement ladderLength for the classic Word Ladder problem.

This Blind 75 version is framed for frontend interviews: write clean JavaScript, name the invariant out loud, and handle edge cases without over-engineering.

What this tests

  • Pattern: BFS shortest transform.
  • Ability to explain time and space complexity clearly.
  • Careful handling of empty inputs, duplicates, and boundary cases.
  • Production-style JavaScript readability, not just competitive-programming shortcuts.

Requirements & constraints

  • →Use JavaScript without external libraries.
  • →Prefer the standard optimal interview approach for this pattern.
  • →Return deterministic output when multiple valid outputs exist where the prompt implies ordering.

Examples

  • Example 1

    Input: Use the canonical Blind 75 sample for this problem.

    Output: Return the value required by the problem statement.

How to approach Word Ladder

The strategy an interviewer expects you to reach for.

Senior Frontend Approach Start by identifying the pattern: BFS shortest transform. Then define the invariant the loop or recursion maintains before writing code.

Premium

The full solution is part of HelloFrontend Pro

The question above is free to read in full. Upgrade to unlock the interactive workspace and the senior-level walkthrough that go with it.

  • Runnable editor with the hidden test suite
  • Progressive hints that unlock as you get stuck
  • Senior-level reference solution with a line-by-line walkthrough
Unlock the full solution →

Already a member? Log in to open the workspace.

More JavaScript Coding questions

View all JavaScript Coding →
JS CodingMedium

Data Merging (Gym Sessions)

JS CodingHard

Data Selection

JS CodingMedium

LRU Cache

JS CodingEasy

Two Sum