Code RoomCount anagram pairs
MediumPrep Room Coding #439

Count anagram pairs

CodingAlgorithms & data structuresEntry–Mid~15 min

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.

0:00 of about 15 min
InputExpectedGot
[["tab","bat","cat","act","atb"]]4not run yetsample