CycleEditDistance (JavaPermutationTools - A Java library for computation on permutations)

java.lang.Object
- org.cicirello.permutations.distance.CycleEditDistance

All Implemented Interfaces:

NormalizedPermutationDistanceMeasurer, NormalizedPermutationDistanceMeasurerDouble, PermutationDistanceMeasurer, PermutationDistanceMeasurerDouble
```
public final class CycleEditDistance
extends Object
implements NormalizedPermutationDistanceMeasurer
```
Cycle edit distance is the minimum number of non-singleton permutation cycles necessary to transform permutation p1 into p2. If p1 equals p2, then this distance is 0. If p1 and p2 have a single permutation cycle, then this distance is clearly 1 since the inverse of that cycle will produce n fixed points. Otherwise, this distance is equal to 2 since it can be shown that at most 2 permutation cycle operations are necessary to transform any permutation of length n into any other. Cycle edit distance satisfies all of the metric properties.

Cycle edit distance was introduced in the following article:

Vincent A. Cicirello. 2022. Cycle Mutation: Evolving Permutations via Cycle Induction, Applied Sciences, 12(11), Article 5506 (June 2022). doi:10.3390/app12115506

Runtime: O(n), where n is the permutation length.

Constructor Summary

Constructors
Constructor Description

CycleEditDistance()
Constructs the distance measurer as specified in the class documentation.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`int`	`distance(Permutation p1, Permutation p2)`	Measures the distance between two permutations.
`int`	`max(int length)`	Computes the maximum possible distance between permutations of a specified length.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.cicirello.permutations.distance.NormalizedPermutationDistanceMeasurer
maxf, normalizedDistance

Methods inherited from interface org.cicirello.permutations.distance.PermutationDistanceMeasurer
distancef

- Constructor Detail
  - CycleEditDistance
```
public CycleEditDistance()
```
    Constructs the distance measurer as specified in the class documentation.
- Method Detail
  - distance
```
public int distance(Permutation p1,
                    Permutation p2)
```
    Measures the distance between two permutations.
    
    Specified by:
    
    distance in interface PermutationDistanceMeasurer
    
    Parameters:
    
    p1 - first permutation
    
    p2 - second permutation
    
    Returns:
    
    distance between p1 and p2
    
    Throws:
    
    IllegalArgumentException - if p1.length() is not equal to p2.length().
  - max
```
public int max(int length)
```
    Description copied from interface: NormalizedPermutationDistanceMeasurer
    
    Computes the maximum possible distance between permutations of a specified length.
    
    Specified by:
    
    max in interface NormalizedPermutationDistanceMeasurer
    
    Parameters:
    
    length - Permutation length.
    
    Returns:
    
    the maximum distance between a pair of permutations of the specified length.