DisjointSetForest (cdk 2.9 API)

java.lang.Object
- org.openscience.cdk.group.DisjointSetForest

```
public class DisjointSetForest
extends Object
```
Implementation of a union-find data structure, largely copied from code due to Derrick Stolee.

Author:

maclean

Belongs to CDK module:
standard

Keywords:

union-find

Constructor Summary

Constructors
Constructor Description

DisjointSetForest(int numberOfElements)
Initialize a disjoint set forest with a number of elements.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`int`	`get(int i)`	Get the value of the forest at this index - note that this will not necessarily give the set for that element : use `getSets()` after union-ing elements.
`int`	`getRoot(int element)`	Travel up the tree that this element is in, until the root of the set is found, and return that root.
`int[][]`	`getSets()`	Retrieve the sets as 2D-array of ints.
`void`	`makeUnion(int elementX, int elementY)`	Union these two elements - in other words, put them in the same set.
`String`	`toString()`

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

- Constructor Detail
  - DisjointSetForest
```
public DisjointSetForest(int numberOfElements)
```
    Initialize a disjoint set forest with a number of elements.
    
    Parameters:
    
    numberOfElements - the number of elements in the forest
- Method Detail
  - get
```
public int get(int i)
```
    Get the value of the forest at this index - note that this will not necessarily give the set for that element : use getSets() after union-ing elements.
    
    Parameters:
    
    i - the index in the forest
    
    Returns:
    
    the value at this index
  - getRoot
```
public int getRoot(int element)
```
    Travel up the tree that this element is in, until the root of the set is found, and return that root.
    
    Parameters:
    
    element - the starting point
    
    Returns:
    
    the root of the set containing element
  - makeUnion
```
public void makeUnion(int elementX,
                      int elementY)
```
    Union these two elements - in other words, put them in the same set.
    
    Parameters:
    
    elementX - an element
    
    elementY - an element
  - getSets
```
public int[][] getSets()
```
    Retrieve the sets as 2D-array of ints.
    
    Returns:
    
    the sets
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object