magpie.utility

Class EqualSumCombinations

java.lang.Object

magpie.utility.EqualSumCombinations

All Implemented Interfaces:

java.lang.Iterable<int[]>

public class EqualSumCombinations
extends java.lang.Object
implements java.lang.Iterable<int[]>

Iterator over all combinations of nonnegative integers that have equal sum.

Example Iteration: (2 0 0) -> (1 1 0) -> (1 0 1) -> (0 2 0) -> (0 1 1) -> (0 0 2)

Constructor Summary

Constructors

Constructor and Description
EqualSumCombinations(int sum, int size) Create an iterator over all possible vectors with a certain number of entries that are all nonnegative integers that sum to the same amount.

Method Summary

Modifier and Type	Method and Description
java.util.List<int[]>	generateAll() Generate all possible vectors
static void	incrementCounter(int[] counter, int sum) Increment a counter that iterates through all possible vectors.
java.util.Iterator<int[]>	iterator()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

EqualSumCombinations

public EqualSumCombinations(int sum,
                            int size)

Create an iterator over all possible vectors with a certain number of entries that are all nonnegative integers that sum to the same amount.

Parameters:

sum - Desired sum (must be greater than 0)

size - Number of integers (must be greater than 1)

Method Detail

iterator

public java.util.Iterator<int[]> iterator()

Specified by:

iterator in interface java.lang.Iterable<int[]>

incrementCounter

public static void incrementCounter(int[] counter,
                                    int sum)

Increment a counter that iterates through all possible vectors. Starts at [0, ..., sum] and ends at [sum, 0, ...].

Parameters:

counter - Counter to be incremented

sum - Sum of elements in vector

generateAll

public java.util.List<int[]> generateAll()

Generate all possible vectors

Returns:

List containing all possible vectors