Package de.sfuhrm.sudoku

Class Creator

java.lang.Object

de.sfuhrm.sudoku.Creator

public final class Creator
extends java.lang.Object

Creates a fully filled sudoku.

Author:

Stephan Fuhrmann

Method Summary

Modifier and Type	Method	Description
static GameMatrix	createFull()	Creates a valid fully setup sudoku.
protected static byte[]	createNumbersToDistribute(java.util.Random r, int multiplicity)	Create a random array with numbers to distribute.
static Riddle	createRiddle(GameMatrix fullMatrix)	Creates a riddle setup sudoku.
static GameMatrix	createVariant(GameMatrix fullyFilled)	Creates a variant of a fully-filled game matrix.
protected static int	getSetBitOffset(int mask, int bitIndex)	Get the index of the nth bit set.
protected static void	swapColumn(GameMatrix matrix, int columnA, int columnB)	Swaps two columns in the given matrix.
protected static void	swapRow(GameMatrix matrix, int rowA, int rowB)	Swaps two rows in the given matrix.

Methods inherited from class java.lang.Object

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

Method Detail

getSetBitOffset

protected static int getSetBitOffset(int mask,
                                     int bitIndex)

Get the index of the nth bit set.

Parameters:

mask - the value to get the bit index from.

bitIndex - the number of the set bit wanted.

Returns:

the index of the relative bitIndex set bit counted from 0, or -1 if there are no more set bits.

createFull

public static GameMatrix createFull()

Creates a valid fully setup sudoku.

Returns:

a fully filled sudoku board. No fields are unset.

createVariant

public static GameMatrix createVariant(GameMatrix fullyFilled)

Creates a variant of a fully-filled game matrix. The variant is calculated very efficiently by applying simple transformations.

Parameters:

fullyFilled - the input matrix to transform. All fields need to be filled.

Returns:

a transformed variant of the input game matrix.

Throws:

java.lang.IllegalArgumentException - if there are unset fields in the GameMatrix.

swapRow

protected static void swapRow(GameMatrix matrix,
                              int rowA,
                              int rowB)

Swaps two rows in the given matrix.

Parameters:

matrix - the game matrix to swap rows in.

rowA - the first row to swap.

rowB - the second row to swap.

swapColumn

protected static void swapColumn(GameMatrix matrix,
                                 int columnA,
                                 int columnB)

Swaps two columns in the given matrix.

Parameters:

matrix - the game matrix to swap rows in.

columnA - the first column to swap.

columnB - the second column to swap.

createNumbersToDistribute

protected static byte[] createNumbersToDistribute(java.util.Random r,
                                                  int multiplicity)

Create a random array with numbers to distribute.

Parameters:

r - the random number generator to use.

multiplicity - the number of times to add the numbers 1 to 9. 1 means adding 1 to 9 only once. 2 means adding 1 to 9 twice.

Returns:

an array with randomly ordered numbers from 1 to 9 with each number occuring multiplicity times.

createRiddle

public static Riddle createRiddle(GameMatrix fullMatrix)

Creates a riddle setup sudoku.

Parameters:

fullMatrix - a fully set up (solved) and valid sudoku. Can be created using createFull() or createVariant(de.sfuhrm.sudoku.GameMatrix) of a full matrix.

Returns:

a maximally cleared sudoku. Contains unset value fields for places where the user/player needs to guess values.

See Also:

createFull(), createVariant(de.sfuhrm.sudoku.GameMatrix)