Theory of automata

turing machines
-decidability and computable enumerability
-mapping reductions, and polynomial reductions
-complexity class: P,NP coNP, PSpace
-NP completness, SAT and examples of NP completness
-Approximation ratios, and examples of approxiamable and unapproxiamable problems
-greedy algorithms
-divide and conquer, recurrence...