+1URL router with single-segment wildcardsCodingBuild a small URL router. - A pattern and a path are split on / into segments. Empty segments are ignored, so /a/b/ is the same as /a/b, and / is the empty path. - A p
Last asked Oct 2026
#trie
- +1
+3Word search with a word search II follow-upCodingFind words on a letter grid by adjacent moves, then extend the solution to finding many words at once efficiently. Reported on 1point3acres' Glean bank; reconstructed in our own…Last asked Sep 2026
+2Greedy longest-match tokenizerCodingImplement a greedy longest-match tokenizer. You are given a string text and a list dictionary. Each entry has the form "<key:<id". key is a non-empty token string and id is its…Last asked Sep 2026
Return every word that starts with a prefixCodingBuild a structure over a word list, once, that answers many prefix queries: for a prefix, return every word in the list that starts with it, without rescanning the whole list. A…Last asked Sep 2026
Highlight categorized phrases in a reviewCodingReviews on a travel site should show key phrases with their category. Write a function that marks every mapped phrase in a review. mapping is a list of (phrase, category) pairs…Last asked Sep 2026- Trie with insert, search and prefix lookupCodingBuild a trie over a dictionary of words. Support inserting a word, checking whether an exact word is present, and returning every word that starts with a typed prefix, as an…Last asked Jul 2026
Shortest unique prefix for each wordCodingGiven a list of distinct words, return for each word its shortest unique prefix: the shortest leading substring of the word that no other word in the list starts with. Return the…Last asked Jun 2026
Store name autocompleteCodingImplement autocomplete over a set of store names: given the prefix typed so far, return the matching stores. Discuss a trie against simpler options, how many results to return and…Last asked May 2026
Radix cache for integer sequences with LRU evictionCodingImplement RadixCache, a cache of integer sequences (for example, token IDs of model prompts) stored in a radix tree: a trie whose edges hold runs of integers instead of single…Last asked Jan 2026- +1Bracket the first matching substring in each wordCodingImplement wrapsubstrings(s: str, elements: liststr) - str. s is a sentence of words separated by single spaces. elements is a list of strings. For each word in s, find the first…Last asked Jan 2026
Autocomplete with top-k suggestionsCodingGiven a list of past queries with their counts, build an autocomplete: for a prefix the user has typed, return the k most popular completions. Use a trie, and discuss storing top…Last asked Sep 2025- Implement a trie (prefix tree)CodingImplement a prefix tree over strings: insert a word, check whether a whole word is present, and check whether any stored word starts with a given prefix. Design the classes so…Last asked Aug 2025
- Predictive text for a phone keypadCodingOn a phone keypad each digit maps to several letters (2 = abc, 3 = def, ...). Given a dictionary and a sequence of digit presses, return the words the sequence could spell, T9…Last asked Jun 2025
Key-value store with prefix searchCodingBuild an in-memory key-value store whose values can also be looked up by key prefix. Keys are strings and values are integers. Implement the KVStore class: - KVStore() creates an…- IP routing table with longest prefix matchCodingBuild the forwarding table of an IPv4 router. Routes are CIDR prefixes mapped to a next-hop name. When a packet arrives, the router must send it to the next hop of the most…
- Detect disguised abusive words in commentsCodingA comment platform wants to catch abusive words that users disguise with look-alike characters, such as $ for s or 0 for o. Implement AbuseDetector: - AbuseDetector(banned…