Code Room
CodingMediumcod-g1257
Subject HashingLevel Entry–Mid~15 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

Given a list of lowercase words, count how many unordered index pairs (i, j) with i < j hold words that are anagrams of each other — identical letters with identical multiplicities, such as "tab" and "bat". Identical words are trivially anagrams, so repeated words form pairs too. For example, ["tab", "bat", "cat", "act", "atb"] has the anagram family {tab, bat, atb} contributing three pairs and {cat, act} contributing one, for an answer of 4. Comparing all pairs directly is O(n^2) — group first instead.

Implement
anagram_pairs(words: list[str]) → int
Examples
in[["tab","bat","cat","act","atb"]]out4
What a strong answer looks like

State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.

Vibe coding: describe the solution in plain language (or narrate it) and the coach grades your approach. Generating runnable code from your description is coming next.

Run or narrate your approach, then ask the coach.