Strings -> Regular Expressions / Finite Automata

Theory-breadth string lane for Thompson-style epsilon-NFA construction and full-string regex membership under a small regex syntax.

• Topic slug: strings/regex-finite-automata
• Tutorial page: Open tutorial
• Ladder page: Open ladder
• Repo problems currently tagged here: 1
• Repo companion pages: 5
• Curated external problems: 1

Microtopics

• regex-syntax
• implicit-concatenation
• postfix-conversion
• thompson-construction
• epsilon-closure
• nfa-simulation

Learning Sources

Source	Type
Algorithms 4/e regular expressions	Course

Repo Companion Material

Material	Type
Regex / Finite Automata hot sheet	quick reference
Template Library exact starter route	starter route
Regex Membership note	anchor note
KMP	compare point
Aho-Corasick	compare point

Curated External Problems

Core

Problem	Source	Difficulty	Context	Style	Prerequisites	Tags	Why it fits
Regex Membership Benchmark	Algorithms 4/e	Medium	Regular-Expressions, Finite-Automata	Automaton Construction; Simulation	Implicit Concatenation; Postfix Conversion; Epsilon Closure	Thompson Nfa; Epsilon Closure; Regex Membership	Canonical textbook benchmark where the whole lesson is regex-to-postfix, Thompson construction, and active-state-set simulation rather than library regex semantics.

Repo Problems

Code	Title	Fit	Difficulty	Pattern	Note	Solution
REGEXMEMBERSHIP	Regex Membership	primary	medium	-	Note	Code

Regeneration

python3 scripts/generate_problem_catalog.py