About the Book
Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Pages: 62. Chapters: Complexity classes, P versus NP problem, NP-hard, PSPACE-complete, Co-NP, EXPTIME, P-complete, NC, Sharp-P-complete, Co-NP-complete, EXPSPACE, NP-easy, NP-equivalent, Arithmetical hierarchy, FO, Time hierarchy theorem, Polynomial hierarchy, SL, Reduction, Immerman-Szelepcsenyi theorem, Space hierarchy theorem, Sipser-Lautemann theorem, NL, List of complexity classes, Resource bounded measure, ACC0, P/poly, ELEMENTARY, PPAD, Savitch's theorem, DTIME, Polynomial-time approximation scheme, Strongly NP-complete, NEXPTIME, DSPACE, Blum axioms, Pseudo-polynomial time, APX, SNP, Parity P, NP-Intermediate, FP, 2-EXPTIME, Valiant-Vazirani theorem, FNP, PPP, UP, PH, Weakly NP-complete, TC0, NSPACE, NL-complete, PolyL, FL, AC0, TFNP, Low and high hierarchies, Toda's theorem, NTIME, Exponential hierarchy, Compression theorem, PLS, LOGCFL, Random-access Turing machine, LH, GapP, DLOGTIME, L/poly, NONELEMENTARY, ALL, ESPACE, QP. Excerpt: The P versus NP problem is a major unsolved problem in computer science. Informally, it asks whether every problem whose solution can be efficiently checked by a computer can also be efficiently solved by a computer. It was introduced in 1971 by Stephen Cook in his paper "The complexity of theorem proving procedures" and is considered by many to be the most important open problem in the field. It is one of the seven Millennium Prize Problems selected by the Clay Mathematics Institute to carry a US$ 1,000,000 prize for the first correct solution. In essence, the P = NP problem can be restated as the following question: The theoretical notion of quick used here is an algorithm that runs in polynomial time. The general class of questions for which some algorithm can provide an answer in polynomial time is called "class P" or just "P." For some questions, there is no known way to find an answer quick...
