← read.ai Interview Insights

read.ai·Software Engineer·Technical Phone Screen·Intermediate

Intermediate
May 2026

Summary

Got a coding question from read.ai that was basically a string similarity problem. Pretty standard algorithmic stuff, nothing too wild, but the edge cases are where it gets you.

Questions Asked (1)

Q1

Given two sentences as arrays of words and a list of similar word pairs, determine if the two sentences are similar. Sentences are similar if they're the same length and every pair of corresponding words is either identical or listed as similar (similarity is not transitive, and order within a pair doesn't matter).

Algorithms & Data Structures
Author's notes

I jumped straight to coding before fully thinking through the edge cases.

Create a free account to read the full note

AI HintsAI Generated

Suggested Approach

First, check if the two sentences have the same length; if not, return false immediately. Then, iterate through each word pair and verify that they are either identical or form a similar pair by checking against a set of normalized pairs (e.g., sorted tuples). If all pairs pass, return true; otherwise, return false.

Pro tip: Mention that similarity is not transitive and order doesn't matter, so you'll store pairs in a set with sorted tuples to ensure O(1) lookups and avoid directional issues. Also, clarify that you assume the input is well-formed and that the list of similar pairs may contain duplicates.

1. Clarify requirements and edge cases

Confirm that sentences are arrays of words, similarity is not transitive, order within a pair doesn't matter, and sentences must be the same length. Ask about case sensitivity and whether words can be empty.

2. Preprocess similar pairs

Convert each similar pair into a normalized form (e.g., sort the two words alphabetically) and store them in a hash set for O(1) lookup.

3. Check length equality

If the lengths of the two sentences differ, immediately return false.

4. Iterate and validate word pairs

For each index i, if words are not identical, check if the normalized pair (sorted) exists in the set. If any pair fails, return false.

5. Return result and analyze complexity

If all pairs pass, return true. State time complexity O(n + m) where n is sentence length and m is number of similar pairs, and space complexity O(m) for the set.

Key Points to Mention

  • Length check as a quick fail-fast condition.
  • Normalization of similar pairs to handle order independence (e.g., sorting the two words).
  • Using a hash set for O(1) membership checks.
  • Similarity is not transitive, so we only check direct pairs, not chains.
  • Time and space complexity analysis.
  • Edge cases: empty sentences, duplicate pairs, and words that are similar to themselves.

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.