define a problem
21Zarankiewicz problem — In the mathematical field of extremal graph theory, the Zarankiewicz problem asks how many edges can be added to a bipartite graph while avoiding a specific bipartite subgraph. Initially, the Polish mathematician K. Zarankiewicz proposed the… …
22Word problem for groups — In mathematics, especially in the area of abstract algebra known as combinatorial group theory, the word problem for a recursively presented group G is the algorithmic problem of deciding whether two words represent the same element. Although it… …
23Clique problem — The brute force algorithm finds a 4 clique in this 7 vertex graph (the complement of the 7 vertex path graph) by systematically checking all C(7,4)=35 4 vertex subgraphs for completeness. In computer science, the clique problem refers to any of… …
24P versus NP problem — Unsolved problems in computer science Is P = NP ? …
25Decision problem — A decision problem has only two possible outputs, yes or no (or alternately 1 or 0) on any input. In computability theory and computational complexity theory, a decision problem is a question in some formal system with a yes or no answer,… …
26Subset sum problem — In computer science, the subset sum problem is an important problem in complexity theory and cryptography. The problem is this: given a set of integers, does the sum of some non empty subset equal exactly zero? For example, given the set { −7, −3 …
27Undecidable problem — In computability theory and computational complexity theory, an undecidable problem is a decision problem for which it is impossible to construct an algorithm that leads to a yes or no answer the problem is not decidable.A decision problem is any …
28Shortest path problem — A graph with 6 vertices and 7 edges In graph theory, the shortest path problem is the problem of finding a path between two vertices (or nodes) in a graph such that the sum of the weights of its constituent edges is minimized. An example is… …
29Burnside's problem — The Burnside problem, posed by William Burnside in 1902 and one of the oldest and most influential questions in group theory, asks whether a finitely generated group in which every element has finite order must necessarily be a finite group. In… …
30Inverse problem — An inverse problem is a general framework that is used to convert observed measurements into information about a physical object or system that we are interested in. For example, if we have measurements of the Earth s gravity field, then we might …
