Yelp Coding Interview Questions
25 Yelp coding interview problems with full optimal solutions — 15 easy, 7 medium, 3 hard. Every problem ships with multiple approaches (brute-force first, then the optimal), complexity tables for each, company-specific tips on what an Yelp interviewer values, and a FAQ section.
Showing 7 problems of 25
- #16mediumfoundational
16. Longest Substring Without Repeating Characters
Find the length of the longest substring with all distinct characters — Yelp uses this sliding-window pattern to test whether candidates can scale to deduping review n-grams.
- #17mediumfoundational
17. Longest Palindromic Substring
Find the longest palindromic substring in a string — Yelp uses expand-from-center to test a candidate's ability to find structural patterns inside long review text bodies.
- #18mediumfoundational
18. 3Sum
Find all unique triplets in an array that sum to zero — Yelp uses sort + two-pointer to test whether candidates can dedupe and scale before tackling geo-clustered triplet matching.
- #19mediumfoundational
19. Group Anagrams
Group an array of strings by anagram class — Yelp uses this canonicalization pattern to test whether candidates can bucket reviews by stable signature for fraud clustering.
- #20mediumfoundational
20. Merge Intervals
Merge a list of overlapping intervals — Yelp uses sort + sweep to test whether candidates can collapse adjacent business-hours ranges before scaling to geo-cell overlap merging.
- #21mediumfoundational
21. Number of Islands
Count connected components of '1's in a 2D grid — Yelp uses flood-fill to test whether candidates can scale grid traversal to geo-cell clustering of dense business regions.
- #22mediumfoundational
22. Kth Largest Element in an Array
Find the kth largest element in an unsorted array — Yelp uses min-heap-of-size-k to test whether candidates can scale top-k selection to a top-rated-businesses leaderboard.