cc.redberry.core.combinatorics

Class IntDistinctTuplesPort

java.lang.Object

cc.redberry.core.combinatorics.IntDistinctTuplesPort

All Implemented Interfaces:

IntCombinatorialPort, OutputPort<int[]>

public class IntDistinctTuplesPort
extends java.lang.Object
implements IntCombinatorialPort

This class represents an iterator (implemented in the output port pattern) over all distinct N-tuples, which can be chosen from N sets of integers. More formally, for N integer arrays: array₁, array₂,...,array_N, this class allows to iterate over all possible integer arrays of the form [i₁, i₂,...,i_N], where all numbers numbers i_j are different and i₁ is chosen from array₁, i₂ is chosen from array₂ and so on.

Consider the example:

 int[] a1 = {1, 2, 3};
 int[] a2 = {2, 3};
 DistinctCombinationsPort dcp = new DistinctCombinationsPort(a1, a2);
 int[] tuple;
 while ((tuple = dcp.take()) != null)
      System.out.println(Arrays.toString(tuple));
 

This code will produce the following sequence:

 [1, 2]
 [1, 3]
 [2, 3]
 [3, 2]
 

This class is implemented via output port pattern and the calculation of the next tuple occurs only on the invocation of take().

Note: method take() returns the same reference on each invocation. So, if it is needed not only to obtain the information from take(), but also save the result, it is necessary to clone the returned array.

Since:

1.0

Nested Class Summary

Nested classes/interfaces inherited from interface cc.redberry.core.utils.OutputPort

OutputPort.PortIterable<T>, OutputPort.PortIterator<T>, OutputPort.Singleton<T>

Constructor Summary

Constructors

Constructor and Description
IntDistinctTuplesPort(int[]... sets)

Method Summary

Modifier and Type	Method and Description
int[]	getReference() Returns the reference to the current iteration element.
void	reset() Resets the iteration
int[]	take() Calculates and returns the next tuple, or null if no more distinct tuples exist.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

IntDistinctTuplesPort

public IntDistinctTuplesPort(int[]... sets)

Method Detail

take

public int[] take()

Calculates and returns the next tuple, or null if no more distinct tuples exist.

Specified by:

take in interface IntCombinatorialPort

Specified by:

take in interface OutputPort<int[]>

Returns:

the next tuple, or null if no more distinct tuples exist

reset

public void reset()

Description copied from interface: IntCombinatorialPort

Resets the iteration

Specified by:

reset in interface IntCombinatorialPort

getReference

public int[] getReference()

Description copied from interface: IntCombinatorialPort

Returns the reference to the current iteration element.

Specified by:

getReference in interface IntCombinatorialPort

Returns:

the reference to the current iteration element