twophase

Class TwoPhase

java.lang.Object

twophase.TwoPhase

public class TwoPhase
extends Object

Field Summary

Fields

Modifier and Type	Field and Description
(package private) static int[]	ax The axis of the move (U,R,F,D,L,B)
(package private) static int[]	flip corners orientation coordinates
(package private) static int[]	FRtoBR
(package private) static int[]	minDistPhase1
(package private) static int[]	minDistPhase2
(package private) static int[]	parity
(package private) static int[]	po The power of the move (90, 180 or -90 degrees)
(package private) static int[]	slice UD slice coordinates (phase 1)
private static String	SOVED_CUBE
(package private) static int[]	twist edges orientation coordinates
(package private) static int[]	UBtoDF
(package private) static int[]	URFtoDLF
(package private) static int[]	URtoDF
(package private) static int[]	URtoUL

Constructor Summary

Constructors

Constructor and Description
TwoPhase()

Method Summary

Methods

Modifier and Type	Method and Description
private static void	createMovesList(List<Move> moves, int depth) Creates the list of moves that was found for solving the cube
static int	findSolution(String cube, int maxDepth, long timeOut, List<Move> moves) Finds list of moves for solving received cube with no more than @maxDepth moves.
static int	findSolution(String cube, int maxDepth, long timeOut, List<Move> moves, String pattern) Finds list of moves for solving received cube with no more than @maxDepth moves.
private static int	totalDepth(int depthPhase1, int maxDepth) Apply phase2 of algorithm and return the combined phase1 and phase2 depth.
private static int	validateCubeString(String cube, CubieCube cubieCube) Validates input cube string and returns a corresponding error code.

Methods inherited from class java.lang.Object

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

Field Detail

ax

static int[] ax

The axis of the move (U,R,F,D,L,B)

po

static int[] po

The power of the move (90, 180 or -90 degrees)

flip

static int[] flip

corners orientation coordinates

twist

static int[] twist

edges orientation coordinates

slice

static int[] slice

UD slice coordinates (phase 1)

parity

static int[] parity

URFtoDLF

static int[] URFtoDLF

FRtoBR

static int[] FRtoBR

URtoDF

static int[] URtoDF

URtoUL

static int[] URtoUL

UBtoDF

static int[] UBtoDF

minDistPhase1

static int[] minDistPhase1

minDistPhase2

static int[] minDistPhase2

SOVED_CUBE

private static final String SOVED_CUBE

See Also:

Constant Field Values

Constructor Detail

TwoPhase

public TwoPhase()

Method Detail

findSolution

public static int findSolution(String cube,
               int maxDepth,
               long timeOut,
               List<Move> moves,
               String pattern)

Finds list of moves for solving received cube with no more than @maxDepth moves. This function allows to select the destination cube using the pattern parameter.

Parameters:

cube - - the cube definition string. The format is a 54 long string containing the characters U, R, F, D, L and B where each char corresponds to the color of a facelet. Faceletes colors should appear in the following order: U1 U2 ... U9 R1 R2 ... R9 F1 F2 ... F9 D1 D2 ... D9 L1 L2 ... L9 B1 B2 ... B9 see Facelet for more info about the format.

maxDepth - - defines the maximal allowed maneuver length. For random cubes, a maxDepth of 21 usually will return a solution in less than 0.5 seconds. With a maxDepth of 20 it takes a few seconds on average to find a solution, but it may take much longer for specific cubes.

timeOut - - defines the maximum computing time of the method in seconds. If it does not return with a solution, it returns with an error code.

moves - - a list to contain suggested solution moves. If a solution was found, the list is cleared before adding the required moves to it. Otherwise, the list remains the same.

pattern - - the desired pattern definition string. The returned list of moves can bring entered cube to this pattern (and not to the standard solved cube). The format should be like cube's foramt.

Returns:

0 if a solution was found, and error code otherwise:
-1: There are not exactly 9 facelets of each color
-2: Not all 12 edges exist exactly once
-3: Flip error: One edge has to be flipped
-4: Not all corners exist exactly once
-5: Twist error: One corner has to be twisted
-6: Parity error: Two corners or two edges have to be exchanged
-7: No solution exists for the given maxDepth
-8: Timeout, no solution within given time 1: There are not exactly 9 facelets of each color in pattern
2: Not all 12 edges exist exactly once in pattern
3: Flip error: One edge has to be flipped in pattern
4: Not all corners exist exactly once in pattern
5: Twist error: One corner has to be twisted in pattern
6: Parity error: Two corners or two edges have to be exchanged in pattern

findSolution

public static int findSolution(String cube,
               int maxDepth,
               long timeOut,
               List<Move> moves)

Finds list of moves for solving received cube with no more than @maxDepth moves.

Parameters:

cube - - the cube definition string. The format is a 54 long string containing the characters U, R, F, D, L and B where each char corresponds to the color of a facelet. Faceletes colors should appear in the following order: U1 U2 ... U9 R1 R2 ... R9 F1 F2 ... F9 D1 D2 ... D9 L1 L2 ... L9 B1 B2 ... B9 see Facelet for more info about the format.

maxDepth - - defines the maximal allowed maneuver length. For random cubes, a maxDepth of 21 usually will return a solution in less than 0.5 seconds. With a maxDepth of 20 it takes a few seconds on average to find a solution, but it may take much longer for specific cubes.

timeOut - - defines the maximum computing time of the method in seconds. If it does not return with a solution, it returns with an error code.

moves - - a list to contain suggested solution moves. If a solution was found, the list is cleared before adding the required moves to it. Otherwise, the list remains the same.

Returns:

0 if a solution was found, and error code otherwise:
-1: There is not exactly one facelet of each color
-2: Not all 12 edges exist exactly once
-3: Flip error: One edge has to be flipped
-4: Not all corners exist exactly once
-5: Twist error: One corner has to be twisted
-6: Parity error: Two corners or two edges have to be exchanged
-7: No solution exists for the given maxDepth
-8: Timeout, no solution within given time

validateCubeString

private static int validateCubeString(String cube,
                     CubieCube cubieCube)

Validates input cube string and returns a corresponding error code. If the string represents a valid cube, entered cubieCube will contain cube's cubie representation

Parameters:

cube - - the cube string to validate

cubieCube - - cubie representation of the cube represented by the string (valid only when string is valid)

Returns:

0 in case of a valid string, and error code otherwise:
-1: There is not exactly one facelet of each color
-2: Not all 12 edges exist exactly once
-3: Flip error: One edge has to be flipped
-4: Not all corners exist exactly once
-5: Twist error: One corner has to be twisted
-6: Parity error: Two corners or two edges have to be exchanged

createMovesList

private static void createMovesList(List<Move> moves,
                   int depth)

Creates the list of moves that was found for solving the cube

Parameters:

moves - - the list to contain the moves for solving the cube

depth - - the depth of the solution that was found (number of moves)

totalDepth

private static int totalDepth(int depthPhase1,
             int maxDepth)

Apply phase2 of algorithm and return the combined phase1 and phase2 depth. In phase2, only the moves U,D,R2,F2,L2 and B2 are allowed.

Parameters:

depthPhase1 - is the maneuver length phase1 that led to this phase2 search

maxDepth - defines the maximal allowed maneuver length

Returns:

total maneuver length