| 3 | import static solver.Utils.suff; |
| 4 | |
| 5 | public class Cube2Face { |
| 6 | private static short[][] facemv = new short[10626][3]; |
| 7 | private static byte[] prun = new byte[10626]; |
| 8 | private static int[] seq = new int[7]; |
| 9 | private static int[] solved = {1819, 0, 4844, 69, 494, 10625}; |
| 10 | |
| 11 | private static void init() { |
| 12 | int[] arr = new int[24]; |
| 13 | for (int i = 0; i < 10626; i++) { |
| 14 | prun[i] = -1; |
| 15 | for (int j = 0; j < 3; j++) { |
| 16 | Utils.idxToComb(arr, i, 4, 24); |
| 17 | switch (j) { |
| 18 | case 0: //U |
| 19 | Utils.circle(arr, 0, 2, 3, 1); |
| 20 | Utils.circle(arr, 4, 20, 16, 8); |
| 21 | Utils.circle(arr, 5, 21, 17, 9); |
| 22 | break; |
| 23 | case 1: //R |
| 24 | Utils.circle(arr, 4, 6, 7, 5); |
| 25 | Utils.circle(arr, 1, 9, 13, 22); |
| 26 | Utils.circle(arr, 3, 11, 15, 20); |
| 27 | break; |
| 28 | case 2: //F |
| 29 | Utils.circle(arr, 8, 10, 11, 9); |
| 30 | Utils.circle(arr, 2, 19, 13, 4); |
| 31 | Utils.circle(arr, 3, 17, 12, 6); |
| 32 | break; |
| 33 | } |
| 34 | facemv[i][j] = (short) Utils.combToIdx(arr, 4, 24); |
| 35 | } |
| 36 | } |
| 37 | for (int i = 0; i < 6; i++) prun[solved[i]] = 0; |
| 38 | Utils.createPrun(prun, 5, facemv, 3); |
| 39 | } |
| 40 | |
| 41 | static { |
| 42 | init(); |
| 43 | } |
| 44 | |
| 45 | private static boolean search(int face, int d, int lm) { |
| 46 | if (d == 0) return prun[face] == 0; |
| 47 | if (prun[face] > d) return false; |
| 48 | for (int i = 0; i < 3; i++) |
| 49 | if (i != lm) { |
| 50 | int x = face; |
| 51 | for (int j = 0; j < 3; j++) { |
| 52 | x = facemv[x][i]; |
| 53 | if (search(x, d - 1, i)) { |
| 54 | seq[d] = i * 3 + j; |
| 55 | return true; |
| 56 | } |
| 57 | } |
| 58 | } |
| 59 | return false; |
| 60 | } |
| 61 | |
| 62 | private static String[] color = {"D: ", "U: ", "L: ", "R: ", "F: ", "B: "}; |