Lexicographic breadth-first search

In computer science, lexicographic breadth-first search or Lex-BFS is a linear time algorithm for ordering the vertices of a graph. The algorithm is different from a breadth-first search, but it produces an ordering that is consistent with breadth-first search.

The lexicographic breadth-first search algorithm is based on the idea of partition refinement and was first developed by Donald J. Rose, Robert E. Tarjan, and George S. Lueker (1976). A more detailed survey of the topic is presented by Corneil (2004). It has been used as a subroutine in other graph algorithms including the recognition of chordal graphs, and optimal coloring of distance-hereditary graphs.