1. The task of finding the number of elements of some set with a particular property. Such counting problems are usually encountered in combinatorics.
2. The task of counting the number of solutions to a problem. For example, to find the number of spanning trees of a given graph, there is a formula in terms of the determinant of a certain matrix that is computable in polynomial time. However there are other problems, like counting the number of Hamiltonian cycles in a given graph, that are expected to be difficult, because determining whether or not a graph has a Hamiltonian cycle is NP-complete (see P=NP question). Although it is possible to determine whether or not a graph has a perfect matching (a set of edges that do not meet each other but meet every vertex) in polynomial time, computing the number of such matchings can be done in polynomial time only if P=NP.
The matching problem referred to is, in the bipartite case, the same as computing the permanent of a 0–1 matrix, for which no good methods are known.
"counting problem." A Dictionary of Computing. . Encyclopedia.com. (February 15, 2019). https://www.encyclopedia.com/computing/dictionaries-thesauruses-pictures-and-press-releases/counting-problem
"counting problem." A Dictionary of Computing. . Retrieved February 15, 2019 from Encyclopedia.com: https://www.encyclopedia.com/computing/dictionaries-thesauruses-pictures-and-press-releases/counting-problem
Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).
Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.
Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:
Modern Language Association
The Chicago Manual of Style
American Psychological Association
- Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
- In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.