{
  "id": 10714581,
  "title": "Aho-Corasick Algorithm",
  "url": "https://urgent.news/2026/09/29/aho-corasick-algorithm",
  "topic": "tech",
  "section": "Tech",
  "published": "2026-09-29T14:49:08.000Z",
  "source": {
    "name": "Lobsters",
    "slug": "lobsters",
    "url": "https://compiler.club/aho-corasick/"
  },
  "original_language": "en",
  "account": "The Aho-Corasick algorithm is a method for simultaneously searching multiple substrings within a sequence. It constructs an automaton from a tree-like data structure known as a trie, which is used to store a set of strings. Each edge in the trie is labeled with a character, and each node represents the concatenation of edge characters required to reach it, starting from the root. Tries aim to minimize redundancy by associating common prefixes.\n\nWhen searching for patterns, the Aho-Corasick automaton transitions through states based on the input characters. If a transition fails, the automaton uses suffix links to recover and continue searching for other patterns. Suffix links are computed using a breadth-first traversal of the trie, ensuring that the longest suffix of the string represented by each node that is also a prefix of a pattern in the trie is preserved.\n\nOutput links are another crucial component of the Aho-Corasick algorithm. These links, similar to suffix links, point to nodes representing shorter strings (visited first in the breadth-first algorithm). Output links are used to identify and output patterns when entering a state represented by an output node. If a node has an output pattern associated with it, it indicates that a match should be output when entering that state. However, if a node's output pattern has a suffix that also represents a pattern in the trie, both patterns should be output simultaneously. This dual functionality allows for efficient and simultaneous pattern matching within the input sequence.",
  "summary": null,
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}