co.cask.coopr.layout

Class SlottedCombinationIterator

java.lang.Object

co.cask.coopr.layout.SlottedCombinationIterator

All Implemented Interfaces:

Iterator<int[]>

public class SlottedCombinationIterator
extends Object
implements Iterator<int[]>

Iterator through all possibilities of X items placed into Y slots, where as many of the leftmost slots are used up as possible. For example, with 3 items and 4 slots, the iterator would enumerate all possibilities like so: 3, 0, 0, 0 2, 1, 0, 0 2, 0, 1, 0 2, 0, 0, 1 1, 2, 0, 0 1, 1, 1, 0 1, 1, 0, 1 1, 0, 2, 0 1, 0, 1, 1 1, 0, 0, 2 0, 3, 0, 0 0, 2, 1, 0 0, 2, 0, 1 0, 1, 2, 0 ... Also supports passing in an array specifying the max number of items that can be placed in any given slot. If no max counts are given, the max defaults to the integer max.

Constructor Summary

Constructors

Constructor and Description
SlottedCombinationIterator(int[] initialState) Create an iterator that starts at the initial state given.
SlottedCombinationIterator(int[] initialState, int[] maxCounts) Create an iterator that starts at the initial state given, and which uses the given max counts.
SlottedCombinationIterator(int numSlots, int numItems) Create an iterator with the number of slots given and the number of items given.
SlottedCombinationIterator(int numSlots, int numItems, int[] maxCounts) Create an iterator with the number of slots given and the number of items given, with a maximum number of items in each slot specified by the max counts array.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	hasNext()
int[]	next()
void	remove()

Methods inherited from class java.lang.Object

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

Constructor Detail

SlottedCombinationIterator

public SlottedCombinationIterator(int[] initialState)

Create an iterator that starts at the initial state given.

Parameters:

initialState - inital state to use.

SlottedCombinationIterator

public SlottedCombinationIterator(int[] initialState,
                          int[] maxCounts)

Create an iterator that starts at the initial state given, and which uses the given max counts.

Parameters:

initialState - inital state to use.

maxCounts - Maximum number of items each slot can have. Null means each slot can have integer max.

SlottedCombinationIterator

public SlottedCombinationIterator(int numSlots,
                          int numItems)

Create an iterator with the number of slots given and the number of items given.

Parameters:

numSlots - Number of slots to use.

numItems - Number of items to use.

SlottedCombinationIterator

public SlottedCombinationIterator(int numSlots,
                          int numItems,
                          int[] maxCounts)

Create an iterator with the number of slots given and the number of items given, with a maximum number of items in each slot specified by the max counts array. The first combination returned will be the first valid combination given the maximum constraints.

Parameters:

numSlots - Number of slots to use.

numItems - Number of items to use.

maxCounts - Maximum number of items each slot can have. Null means each slot can have integer max.

Method Detail

hasNext

public boolean hasNext()

Specified by:

hasNext in interface Iterator<int[]>

next

public int[] next()

Specified by:

next in interface Iterator<int[]>

remove

public void remove()

Specified by:

remove in interface Iterator<int[]>