The four groups

  • Sorting algorithms

    QUICKSORT · MERGESORT · BUBBLE · INSERTION

  • Big-O complexity classes

    POLYNOMIAL · QUADRATIC · LOGARITHMIC · CONSTANT

  • Self-balancing tree types

    BINARY · RED-BLACK · AVL · TRIE

  • Words paired with SEARCH

    LINEAR · DEPTH-FIRST · BREADTH-FIRST · ELASTIC

Why this puzzle works

Pure four-way ambiguity puzzle. LINEAR can be a complexity class *or* a search type. BINARY can be a tree *or* a search type. Both pulls are real; only one assignment lands four-on-four-on-four-on-four. The way you crack it: green has POLYNOMIAL/QUADRATIC/LOGARITHMIC/CONSTANT — that's already four without LINEAR. So LINEAR has to go purple, which means BINARY can't (purple is full), which means BINARY is a tree. ElasticSearch is the bonus tell that locks purple in. Difficulty-4 puzzle: the trick is *counting*, not pattern-matching.

How to read a Connectle without solving it

A code-themed grouping puzzle rewards counting as much as recognition. Start by listing every plausible group, then notice which tiles appear in two lists. Whichever group has exactly four unambiguous members is your anchor — solve it first and the rest of the board collapses by elimination. The hardest tier (purple) is almost always wordplay: tiles that share a prefix or suffix, not a concept. If a tile feels orphaned, ask whether the same word could follow or precede a common engineering word like root, stack, cache, or queue.