Editing Breadth-first search (section)

=== Completeness ===
In the analysis of algorithms, the input to breadth-first search is assumed to be a finite graph, represented as an [[adjacency list]], [[adjacency matrix]], or similar representation. However, in the application of graph traversal methods in [[artificial intelligence]] the input may be an [[implicit graph|implicit representation]] of an infinite graph. In this context, a search method is described as being complete if it is guaranteed to find a goal state if one exists. Breadth-first search is complete, but depth-first search is not. When applied to infinite graphs represented implicitly, breadth-first search will eventually find the goal state, but depth first search may get lost in parts of the graph that have no goal state and never return.<ref name="coppin">Coppin, B. (2004). Artificial intelligence illuminated. Jones & Bartlett Learning. pp.&nbsp;79–80.</ref>