EulerianTourAlgo (JGAlgo - Parent 0.3.0 API)

```
public interface EulerianTourAlgo
```
Eulerian tour calculation algorithm.
An Eulerian tour is a tour that visits every edge exactly once (allowing for revisiting vertices). For a connected undirected graph, if all vertices have an even degree, an Eulerian cycle will be found. If exactly two vertices have an odd degree, called \(s,t\), an Eulerian tour that start at \(s\) and ends at \(t\) exists. For any other vertices degrees an Eulerian tour does not exists. For a strongly connected directed graph, the in-degree and out-degree of each vertex must be equal for an Eulerian cycle to exists. If exactly one vertex \(s\) has one more out-edge than in-edges, and one vertex \(t\) has one more in-edge than out-edges, an Eulerian tour that start at \(s\) and ends at \(t\) exists.
Use newInstance() to get a default implementation of this interface. A builder obtained via newBuilder() may support different options to obtain different implementations.

Author:

Barak Ugav

See Also:

Wikipedia

Nested Class Summary

Nested Classes
Modifier and Type Interface Description

static interface EulerianTourAlgo.Builder
A builder for EulerianTourAlgo objects.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`<V,E> Path<V,E>`	`computeEulerianTour(Graph<V,E> g)`	Compute an Eulerian tour in the graph that visit all edges exactly once.
`static EulerianTourAlgo.Builder`	`newBuilder()`	Create a new Eulerian tour algorithm builder.
`static EulerianTourAlgo`	`newInstance()`	Create a new Eulerian tour computation algorithm.

- Method Detail
  - computeEulerianTour
```
<V,E> Path<V,E> computeEulerianTour(Graph<V,E> g)
```
    Compute an Eulerian tour in the graph that visit all edges exactly once.
    The graph is assumed to be (strongly) connected. Either a cycle or tour will be found, depending on the vertices degrees.
    If g is IntGraph, the returned object is IPath.
    
    Type Parameters:
    
    V - the vertices type
    
    E - the edges type
    
    Parameters:
    
    g - a graph
    
    Returns:
    
    an Eulerian tour that visit all edges of the graph exactly once
    
    Throws:
    
    IllegalArgumentException - if there is no Eulerian tour in the graph
  - newInstance
```
static EulerianTourAlgo newInstance()
```
    Create a new Eulerian tour computation algorithm.
    This is the recommended way to instantiate a new EulerianTourAlgo object. The EulerianTourAlgo.Builder might support different options to obtain different implementations.
    
    Returns:
    
    a default implementation of EulerianTourAlgo
  - newBuilder
```
static EulerianTourAlgo.Builder newBuilder()
```
    Create a new Eulerian tour algorithm builder.
    Use newInstance() for a default implementation.
    
    Returns:
    
    a new builder that can build EulerianTourAlgo objects