NC (complexity) - Problems in NC

Problems in NC

As with P, by a slight abuse of language, one might classify function problems and search problems as being in NC. NC is known to include many problems, including

  • Integer addition, multiplication and division;
  • Matrix multiplication, determinant, inverse, rank;
  • Polynomial GCD, by a reduction to linear algebra using Sylvester matrix (it is open whether integer GCD is in NC);
  • Finding a maximal matching.

Often algorithms for those problems had to be separately invented and could not be naïvely adapted from well-known algorithms – Gaussian elimination and Euclidean algorithm rely on operations performed in sequence. One might contrast ripple carry adder with a carry-lookahead adder.

Read more about this topic:  NC (complexity)

Famous quotes containing the words problems in and/or problems:

    The proper method of philosophy consists in clearly conceiving the insoluble problems in all their insolubility and then in simply contemplating them, fixedly and tirelessly, year after year, without any hope, patiently waiting.
    Simone Weil (1909–1943)

    In many ways, life becomes simpler [for young adults]. . . . We are expected to solve only a finite number of problems within a limited range of possible solutions. . . . It’s a mental vacation compared with figuring out who we are, what we believe, what we’re going to do with our talents, how we’re going to solve the social problems of the globe . . .and what the perfect way to raise our children will be.
    Roger Gould (20th century)