Class DisjunctCombinatorics

java.lang.Object

com.knezevic.edaf.v3.problems.discrete.disjunct.DisjunctCombinatorics

public final class DisjunctCombinatorics
extends Object

Combinatorial helpers used for exhaustive and sampled validation/evaluation of disjunct matrix properties.

Method Summary

Modifier and Type	Method	Description
static double	binomialCoefficientAsDouble(int n, int k)	Returns n choose k as double for ratio-based metrics.
static long	binomialCoefficientCapped(int n, int k, long cap)	Returns n choose k capped to cap + 1 to avoid overflow.
static void	forEachCombination(int n, int k, Consumer<int[]> visitor)	Iterates all k-combinations of indices [0, n-1] in lexicographic order.
static void	sampleCombination(Random random, int n, int k, int[] output)	Samples one k-combination uniformly without replacement into output.

Methods inherited from class java.lang.Object

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

Method Details

forEachCombination

public static void forEachCombination(int n,
 int k,
 Consumer<int[]> visitor)

Iterates all k-combinations of indices [0, n-1] in lexicographic order.

sampleCombination

public static void sampleCombination(Random random,
 int n,
 int k,
 int[] output)

Samples one k-combination uniformly without replacement into output. Output is sorted increasingly.

binomialCoefficientCapped

public static long binomialCoefficientCapped(int n,
 int k,
 long cap)

Returns n choose k capped to cap + 1 to avoid overflow.

binomialCoefficientAsDouble

public static double binomialCoefficientAsDouble(int n,
 int k)

Returns n choose k as double for ratio-based metrics.