Computer Science Trivia: Theory of Computation
Quick, free theory of computation quiz to test your knowledge. Instant results.
This quiz helps you check your grasp of the theory of computation, including automata, formal languages, and Turing machines. In minutes, try our discrete math quiz, explore a big o notation quiz to sharpen complexity skills, or review broad computer science practice questions for extra drills.
Study Outcomes
- Understand Core Automata Concepts -
Distinguish between deterministic and nondeterministic automata and explain how finite-state machines process input strings in computational theory.
- Classify Formal Languages -
Categorize languages within the Chomsky hierarchy and recognize the differences between regular, context-free, context-sensitive, and recursively enumerable languages.
- Analyze Decidability -
Assess decision problems for decidability and identify classic undecidable problems such as the Halting Problem and Post's Correspondence Problem.
- Apply the Pumping Lemma -
Use the pumping lemma for regular and context-free languages to prove whether a language belongs to a given class.
- Evaluate Complexity Classes -
Differentiate common complexity classes like P, NP, and PSPACE and gauge the computational resources required to solve various problems.
- Identify Knowledge Gaps -
Pinpoint areas for further study by reviewing your scores on CS trivia questions and targeting challenging computational theory topics.
Cheat Sheet
- Finite Automata & Regular Languages -
Deterministic and nondeterministic finite automata (DFA/NFA) form the backbone of regular language theory by processing input symbols in 5-tuple structures (Sipser, 2006). For example, the language 0*1* - which matches any number of 0s followed by 1s - can be recognized by a two-state DFA. Remember "SALT" as a mnemonic for DFA components: States, Alphabet, δ (transition), Start, and Accept.
- Pumping Lemma for Regular Languages -
The pumping lemma provides a proof technique to show certain languages aren't regular by demonstrating that all sufficiently long strings can be "pumped" inside a decomposed segment (Hopcroft & Ullman, 1979). In practice, you assume a pumping length p, split the string xyz with |xy| ≤ p and |y| > 0, and derive a contradiction by showing xyiz ∉ L for some i. Visualize "stretching" the y segment like a rubber band to recall how the lemma works!
- Context-Free Grammars & Pushdown Automata -
Context-free grammars (CFGs) generate languages recognized by pushdown automata (PDA) via production rules like S → (S)S | ε for balanced parentheses (Sipser, 2006). PDAs use a stack to handle nested structures: push on "(" and pop on ")", accepting when the stack empties. A handy mnemonic is "PUSH then POP for proper pairing!"
- Turing Machines & Decidability -
Turing machines extend finite automata with an infinite tape and bidirectional head, formalizing what it means to compute any algorithm (Turing, 1936). The Halting Problem proves there's no general algorithm to decide whether an arbitrary TM halts on a given input, showcasing an undecidable problem (Rice's Theorem). Picture the head spinning endlessly - no stopping criterion - to remember undecidability!
- Complexity Classes P vs NP -
Class P contains problems solvable in polynomial time by a deterministic TM, while NP houses those verifiable in polynomial time by a nondeterministic TM (Cook, 1971). The P vs NP question - "Is P = NP?" - remains one of the seven Millennium Prize Problems and drives much of complexity theory. Think "verifier vs solver" to recall NP's nature of easy checking but potentially hard finding!