Celebrity

In the context of computer science, „celebrity“ refers to a specific problem in social network analysis and graph theory. The celebrity problem involves identifying a person (or node) in a group (or graph) who is known by everyone else in the group but does not know anyone else. Formally, a celebrity is defined as follows:

1. A person A is a celebrity if every other person knows A.
2. A celebrity does not know any other person.

The challenge is to determine whether a celebrity exists in a given group and, if so, to identify them efficiently. This can be performed using various algorithms that examine the relationships within the group, often represented as a directed graph. The problem is interesting for its applications in social network analysis and can demonstrate concepts of knowledge propagation and connectivity within networks.

The celebrity problem is commonly used in algorithm discussions and can be solved in linear time with the appropriate approach, making it a classic example in the study of algorithms and data structures.