org.uacalc.util

Class SequenceGenerator

java.lang.Object

org.uacalc.util.SequenceGenerator

public final class SequenceGenerator
extends java.lang.Object

This has utility static methods for sequence generation, including nondecreasing sequences. It also includes an in-place ArrayIncrementor.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SequenceGenerator()

Method Summary

Modifier and Type	Method and Description
static ArrayIncrementor	increasingSequenceIncrementor(int[] a, int max) This increments an array in place through all strictly increasing sequences whose entries lie between 0 and max, inclusive.
static ArrayIncrementor	increasingSequenceIncrementorOld(int[] a, int max) This increments an array in place through all strictly increasing sequences whose entries lie between 0 and max, inclusive.
static int[]	initialPartition(int size, int numBlocks) This returns the initial partition on size with numBlocks blocks in JB form.
static ArrayIncrementor	leftSequenceIncrementor(int[] a, int max) This just increments the array through all possible tuples with entries between 0 and max from the left.
static void	main(java.lang.String[] args)
static ArrayIncrementor	nondecreasingSequenceIncrementor(int[] a, int max) This increments an array in place through all nondecreasing sequences whose entries lie between 0 and max, inclusive.
static ArrayIncrementor	nondecreasingSequenceIncrementor(int[] a, int max, int lastMin) This increments an array in place through all nondecreasing sequences whose entries lie between 0 and max, inclusive, subject to the restriction that last coordinate is at least lastMin (useful when the first part of a list is known to be closed).
static ArrayIncrementor	partitionArrayIncrementor(int[] a, int numBlocks) This returns an ArrayIncrementor that increments through all partitions with numBlocks blocks in JB form.
static ArrayIncrementor	sequenceIncrementor(int[] a, int max) This just increments the array through all possible tuples with entries between 0 and max.
static ArrayIncrementor	sequenceIncrementor(int[] a, int[] maxs) This just increments the array through all possible tuples with entries between 0 and max.
static ArrayIncrementor	sequenceIncrementor(int[] a, int max, int min) This just increments the array through all possible tuples with entries between 0 and max and having at least one entry at least as large as min.
static ArrayIncrementor	sequenceIncrementor(int[] a, int max, int min, int jump) This just increments the array through all possible tuples with entries between 0 and max and having at least one entry at least as large as min.

Methods inherited from class java.lang.Object

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

Constructor Detail

SequenceGenerator

protected SequenceGenerator()

Method Detail

nondecreasingSequenceIncrementor

public static ArrayIncrementor nondecreasingSequenceIncrementor(int[] a,
                                                                int max)

This increments an array in place through all nondecreasing sequences whose entries lie between 0 and max, inclusive.

nondecreasingSequenceIncrementor

public static ArrayIncrementor nondecreasingSequenceIncrementor(int[] a,
                                                                int max,
                                                                int lastMin)

This increments an array in place through all nondecreasing sequences whose entries lie between 0 and max, inclusive, subject to the restriction that last coordinate is at least lastMin (useful when the first part of a list is known to be closed).

increasingSequenceIncrementorOld

public static ArrayIncrementor increasingSequenceIncrementorOld(int[] a,
                                                                int max)

This increments an array in place through all strictly increasing sequences whose entries lie between 0 and max, inclusive.

Parameters:

a -

max -

Returns:

increasingSequenceIncrementor

public static ArrayIncrementor increasingSequenceIncrementor(int[] a,
                                                             int max)

This increments an array in place through all strictly increasing sequences whose entries lie between 0 and max, inclusive. This is reentrant: you can start with any valid a and it will increment all those above it.

Parameters:

a -

max -

Returns:

sequenceIncrementor

public static ArrayIncrementor sequenceIncrementor(int[] a,
                                                   int max)

This just increments the array through all possible tuples with entries between 0 and max. This increments from the right: [0,0,0], [0,0,1], ...,[max,max,max].

sequenceIncrementor

public static ArrayIncrementor sequenceIncrementor(int[] a,
                                                   int[] maxs)

This just increments the array through all possible tuples with entries between 0 and max. This increments from the right: [0,0,0], [0,0,1], ...,[maxs[0],maxs[1],maxs[2]].

sequenceIncrementor

public static ArrayIncrementor sequenceIncrementor(int[] a,
                                                   int max,
                                                   int min)

This just increments the array through all possible tuples with entries between 0 and max and having at least one entry at least as large as min. This increments from the right: * [0,0,0], [0,0,1], ...,[max,max,max]. Of course min should be at most max.

sequenceIncrementor

public static ArrayIncrementor sequenceIncrementor(int[] a,
                                                   int max,
                                                   int min,
                                                   int jump)

This just increments the array through all possible tuples with entries between 0 and max and having at least one entry at least as large as min. This increments from the right: * [0,0,0], [0,0,1], ...,[max,max,max]. Of course min should be at most max. jump indicates how many times the array will be incremented by each call to increment(). This is used in parallel processing.

leftSequenceIncrementor

public static ArrayIncrementor leftSequenceIncrementor(int[] a,
                                                       int max)

This just increments the array through all possible tuples with entries between 0 and max from the left. This increments from the left: [0,0,0], [1,0,0], ..., [max,max,max].

initialPartition

public static int[] initialPartition(int size,
                                     int numBlocks)

This returns the initial partition on size with numBlocks blocks in JB form. Should be used when using partitionArrayIncrementor.

Parameters:

size -

numBlocks -

Returns:

partitionArrayIncrementor

public static ArrayIncrementor partitionArrayIncrementor(int[] a,
                                                         int numBlocks)

This returns an ArrayIncrementor that increments through all partitions with numBlocks blocks in JB form. JB form is an array a with a[a[i]] = a[i] and a[i] <= i. The initial a must be the first valid partition. It can be obtained using initialPartition.

Parameters:

a -

numBlocks -

Returns:

main

public static void main(java.lang.String[] args)