ECS 120 – Winter 2012 – Lecture Topics

Lecture Topic
Week 1 Lect 01 - T 1/10 Three problems of differing hardness. Strings and languages, and operators on them.
Lect 02 - R 1/12 Regular languages. DFAs and their formalization. Closure properties: complement, union.
Lect 03 - F 1/13 Finishing the product construction. Pigeonhold arguments for DFA size.
Week 2 Lect 04 - T 1/17 Shawn Recker. NFA examples, defn, closure properties. Start NFA-acceptable=DFA-acceptable.
Lect 05 - R 1/19 Quiz 1. Shawn Recker. Finish NFA-acceptable=DFA-acceptable. Reg exps. Reg langs are NFA-acceptable.
Week 3 Lect 06 - T 1/24 Review. Converting an NFA to a regular expression. Showing languages not regular: the pumping lemma.
Lect 07 - R 1/26 More pumping-lemma examples. Decision procedures for regular languages.
Week 4 Lect 08 - T 1/31 DFA minimization. Start context-free languages (examples and vocabulary).
Lect 09 - R 2/02 Quiz 2. More examples of CFLs. Formal definitions for CFLs. Ambiguity.
Week 5 Lect 10 - T 2/07 Review: quiz2, then CFLs. Chomsky Normal Form. Membership testing. CYK algorithm. PDAs.
Lect 11 - R 2/09 Formal definition of PDAs. PDAs accept exactly the CFLs. The pumping lemma for CFLs
Week 6 Lect 12 - T 2/14 Wrap up CFLs: pumping lemma, closure properties. The Chomsky hierarchy. Turing machines.
Lect 13 - R 2/16 Midterm
Week 7 Lect 14 - T 2/21 Formal defn of TMs. An example. Decidable and r.e. languages. Four-possibilies theorem. MT comments.
Lect 15 - T 2/23 TM variants. The Church-Turing thesis. Problem with academic misconduct.
Week 8 Lect 16 - T 2/28 Undecidability of ATM. Reductions (important!) (the many-one variety): definitions and examples.
Lect 17 - R 3/1 More examples of many-one reductions, including Virus Detection, PCP. the tiling problem (or here).
Week 9 Lect 18 - T 3/6 Quiz 3. Undecidability of L(G)=Σ*. The class P. Examples.
Lect 19 - R 3/8 More examples. The class NP (two characterizations). Polynomial-time reductions. NP-Completeness.
Week 10 Lect 20 - T 3/13 Review. Cook-Levin Theorem. Propositions. Showing 3SAT, CLIQUE, and G3C are NP-complete.
Lect 21 - R 3/15 One last reduction: SUBSET SUM. Proof of the Cook-Levin Thm. A glimpse beyond. Evaluations.
Lect xx - F 3/23 Final, 8-10 am