Package com.jgalgo.io

Class Graph6GraphReader

java.lang.Object
com.jgalgo.io.Graph6GraphReader
All Implemented Interfaces:
GraphReader<Integer,Integer>
public final class Graph6GraphReader extends Object
Read a graph in 'graph6' format.

'graph6' is a format for storing undirected graphs in a compact manner, using only printable ASCII characters. Files in these format have text type and contain one line per graph. It is suitable for small graphs, or large dense graphs. The format support graphs with vertices numbered 0..n-1 only, where n is the number of vertices, and edges numbered 0..m-1 only, where m is the number of edges. A graph6 file contains a bit vector with n (n - 1) / 2 bits representing the edges of the graph. All bytes of a graph6 file are in the range 63..126, which are the printable ASCII characters, therefore a bit vector is represented by a sequence of bytes in which each byte encode only 6 bits.

The format does not support specifying the ids of the edges, therefore the reader will number them from 0 to m-1 in the order in the bit vector. The order, and the format details can be found here.

The 'graph6' format is efficient for dense graph, for dense graphs the 'sparse6' format should be used.

Self edges and parallel edges are not supported by the format.

File with a graph in 'graph6' format usually have the extension .g6.

Author:
Barak Ugav
See Also:

  • Constructor Details

    • Graph6GraphReader

      public Graph6GraphReader()
      Create a new reader.

  • Method Details

    • readGraph

      public IntGraph readGraph(Reader reader)
      Description copied from interface: GraphReader
      Read a graph from an I/O reader.
      Parameters:
      reader - an I/O reader that contain a graph description
      Returns:
      a new graph read from the reader

    • readGraph

      public IntGraph readGraph(File file)
      Description copied from interface: GraphReader
      Read a graph from a file.
      Parameters:
      file - a file that contain a graph description
      Returns:
      a new graph read from the file

    • readGraph

      public IntGraph readGraph(String path)
      Description copied from interface: GraphReader
      Read a graph from a file, given a path to it.
      Parameters:
      path - a path to a file that contain a graph description
      Returns:
      a new graph read from the file

    • readIntoBuilder

      public final IntGraphBuilder readIntoBuilder(Reader reader)
      Description copied from interface: GraphReader
      Read a graph from an I/O reader into a GraphBuilder.
      Specified by:
      readIntoBuilder in interface GraphReader<Integer,Integer>
      Parameters:
      reader - an I/O reader that contain a graph description
      Returns:
      a graph builder containing the vertices and edge read from the reader