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cs0x7f
225 Stars 47 Forks 119 Commits 2 Opened issues

Description

Rubik's Cube Solver. An optimized implementation of Kociemba's two-phase algorithm.

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min2phase

  • Rubik's Cube solver or scrambler. Build Status

Usage

import cs.min2phase.Search;
import cs.min2phase.Tools;

public class demo {

public static void simpleSolve(String scrambledCube) {
    String result = new Search().solution(scrambledCube, 21, 100000000, 0, 0);
    System.out.println(result);
    // R2 U2 B2 L2 F2 U' L2 R2 B2 R2 D  B2 F  L' F  U2 F' R' D' L2 R'
}

public static void outputControl(String scrambledCube) {
    String result = new Search().solution(scrambledCube, 21, 100000000, 0, Search.APPEND_LENGTH);
    System.out.println(result);
    // R2 U2 B2 L2 F2 U' L2 R2 B2 R2 D  B2 F  L' F  U2 F' R' D' L2 R' (21f)

    result = new Search().solution(scrambledCube, 21, 100000000, 0, Search.USE_SEPARATOR | Search.INVERSE_SOLUTION);
    System.out.println(result);
    // R  L2 D  R  F  U2 F' L  F' .  B2 D' R2 B2 R2 L2 U  F2 L2 B2 U2 R2
}

public static void findShorterSolutions(String scrambledCube) {
    //Find shorter solutions (try more probes even a solution has already been found)
    //In this example, we try AT LEAST 10000 phase2 probes to find shorter solutions.
    String result = new Search().solution(scrambledCube, 21, 100000000, 10000, 0);
    System.out.println(result);
    // L2 U  D2 R' B  U2 L  F  U  R2 D2 F2 U' L2 U  B  D  R'
}

public static void continueSearch(String scrambledCube) {
    //Continue to find shorter solutions
    Search searchObj = new Search();
    String result = searchObj.solution(scrambledCube, 21, 500, 0, 0);
    System.out.println(result);
    // R2 U2 B2 L2 F2 U' L2 R2 B2 R2 D  B2 F  L' F  U2 F' R' D' L2 R'

    result = searchObj.next(500, 0, 0);
    System.out.println(result);
    // D2 L' D' L2 U  R2 F  B  L  B  D' B2 R2 U' R2 U' F2 R2 U' L2

    result = searchObj.next(500, 0, 0);
    System.out.println(result);
    // L' U  B  R2 F' L  F' U2 L  U' B' U2 B  L2 F  U2 R2 L2 B2

    result = searchObj.next(500, 0, 0);
    System.out.println(result);
    // Error 8, no solution is found after 500 phase2 probes. Let's try more probes.

    result = searchObj.next(500, 0, 0);
    System.out.println(result);
    // L2 U  D2 R' B  U2 L  F  U  R2 D2 F2 U' L2 U  B  D  R'
}

public static void main(String[] args) {
    // Full initialization, which will take about 200ms.
    // The solver will be about 5x~10x slower without full initialization.
    long startTime = System.nanoTime();
    Search.init();
    System.out.println("Init time: " + (System.nanoTime() - startTime) / 1.0E6 + " ms");

    /** prepare scrambledCube as
     *
     *             |************|
     *             |*U1**U2**U3*|
     *             |************|
     *             |*U4**U5**U6*|
     *             |************|
     *             |*U7**U8**U9*|
     *             |************|
     * ************|************|************|************|
     * *L1**L2**L3*|*F1**F2**F3*|*R1**R2**R3*|*B1**B2**B3*|
     * ************|************|************|************|
     * *L4**L5**L6*|*F4**F5**F6*|*R4**R5**R6*|*B4**B5**B6*|
     * ************|************|************|************|
     * *L7**L8**L9*|*F7**F8**F9*|*R7**R8**R9*|*B7**B8**B9*|
     * ************|************|************|************|
     *             |************|
     *             |*D1**D2**D3*|
     *             |************|
     *             |*D4**D5**D6*|
     *             |************|
     *             |*D7**D8**D9*|
     *             |************|
     *
     * -> U1 U2 ... U9 R1 ... R9 F1 ... F9 D1 ... D9 L1 ... L9 B1 ... B9
     */
    String scrambledCube = "DUUBULDBFRBFRRULLLBRDFFFBLURDBFDFDRFRULBLUFDURRBLBDUDL";
    // scrambledCube can also be obtained by specific moves
    scrambledCube = Tools.fromScramble("R L2 D R F U2 F' L F' B2 D' R2 B2 R2 L2 U F2 L2 B2 U2 R2");
    System.out.println(scrambledCube);

    simpleSolve(scrambledCube);
    outputControl(scrambledCube);
    findShorterSolutions(scrambledCube);
    continueSearch(scrambledCube);
}

}

License GPLv3

Copyright (C) 2019  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:.

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