min2phase

Rubik's Cube solver or scrambler.

two-phase algorithm

See Kociemba's page

Feature

Memory: ~1M with twist-flip-pruning table, ~0.5M without twist-flip-pruning table. See Tools.java line 13
Average Solving Time @21 moves: ~10ms without T-F-P table, ~7ms with T-F-P table.
Initialization Time: ~160ms without T-F-P table, ~240ms with T-F-P table.

File Description

Tools.java Many useful functions
Util.java Definitions and some math tools.
CubieCube.java CubieCube, see kociemba's page.
CoordCube.java Only for generating tables.
Search.java Main.
MainProgram.java GUI version.
pruningValue.txt For checking whether the pruning table is generated correctly.

License GPLv3

Copyright (C) 2012  Shuang Chen

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

Some improvements

Conventional two-phase algorithm only find (sub-)optimal solutions to <U,R2,F2,D,L2,B2>. However, If we are able to find more phase1 solutions within a limited depth, the probability of a short solution will increased.

Try different axes

The target of phase1 can be either <U,R2,F2,D,L2,B2>, <U2,R,F2,D2,L,B2>, or <U2,R2,F,D2,L2,B>.

Try the inverse of the state

We will try to solve the inverse state simultaneously to find more phase1 solutions.

Try pre-scramble

We can also use pre-scramble technique (which is widely used in fewest-move challenge) to find more phase1 solutions.

sgelb / min2phase