Use this if you are using igraph from R

has_eulerian_path {igraph} | R Documentation |

`has_eulerian_path`

and `has_eulerian_cycle`

checks whether there
is an Eulerian path or cycle in the input graph. `eulerian_path`

and
`eulerian_cycle`

return such a path or cycle if it exists, and throws
an error otherwise.

```
has_eulerian_path(graph)
has_eulerian_cycle(graph)
eulerian_path(graph)
eulerian_cycle(graph)
```

`graph` |
An igraph graph object |

`has_eulerian_path`

decides whether the input graph has an Eulerian
*path*, i.e. a path that passes through every edge of the graph exactly
once, and returns a logical value as a result. `eulerian_path`

returns
a possible Eulerian path, described with its edge and vertex sequence, or
throws an error if no such path exists.

`has_eulerian_cycle`

decides whether the input graph has an Eulerian
*cycle*, i.e. a path that passes through every edge of the graph exactly
once and that returns to its starting point, and returns a logical value as
a result. `eulerian_cycle`

returns a possible Eulerian cycle, described
with its edge and vertex sequence, or throws an error if no such cycle exists.

For `has_eulerian_path`

and `has_eulerian_cycle`

, a logical
value that indicates whether the graph contains an Eulerian path or cycle.
For `eulerian_path`

and `eulerian_cycle`

, a named list with two
entries:

`epath` |
A vector containing the edge ids along the Eulerian path or cycle. |

`vpath` |
A vector containing the vertex ids along the Eulerian path or cycle. |

```
g <- make_graph( ~ A-B-C-D-E-A-F-D-B-F-E )
has_eulerian_path(g)
eulerian_path(g)
has_eulerian_cycle(g)
## Not run: eulerian_cycle(g)
```

[Package *igraph* version 1.3.4 Index]