// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// 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.
internal static int totalDepth(int depthPhase1, int maxDepth)
{
int mv = 0, d1 = 0, d2 = 0;
int maxDepthPhase2 = Math.Min(10, maxDepth - depthPhase1); // Allow only max 10 moves in phase2
for (int i = 0; i < depthPhase1; i++)
{
mv = 3 * ax[i] + po[i] - 1;
URFtoDLF[i + 1] = CoordCubeBuildTables.URFtoDLF_Move[URFtoDLF[i], mv];
FRtoBR[i + 1] = CoordCubeBuildTables.FRtoBR_Move[FRtoBR[i], mv];
parity[i + 1] = CoordCubeBuildTables.parityMove[parity[i]][mv];
}
if ((d1 = CoordCubeBuildTables.getPruning(CoordCubeBuildTables.Slice_URFtoDLF_Parity_Prun, (CoordCubeBuildTables.N_SLICE2 * URFtoDLF[depthPhase1] + FRtoBR[depthPhase1]) * 2 + parity[depthPhase1])) > maxDepthPhase2)
{
return(-1);
}
for (int i = 0; i < depthPhase1; i++)
{
mv = 3 * ax[i] + po[i] - 1;
URtoUL[i + 1] = CoordCubeBuildTables.URtoUL_Move[URtoUL[i], mv];
UBtoDF[i + 1] = CoordCubeBuildTables.UBtoDF_Move[UBtoDF[i], mv];
}
URtoDF[depthPhase1] = CoordCubeBuildTables.MergeURtoULandUBtoDF[URtoUL[depthPhase1], UBtoDF[depthPhase1]];
if ((d2 = CoordCubeBuildTables.getPruning(CoordCubeBuildTables.Slice_URtoDF_Parity_Prun, (CoordCubeBuildTables.N_SLICE2 * URtoDF[depthPhase1] + FRtoBR[depthPhase1]) * 2 + parity[depthPhase1])) > maxDepthPhase2)
{
return(-1);
}
if ((minDistPhase2[depthPhase1] = Math.Max(d1, d2)) == 0) // already solved
{
return(depthPhase1);
}
// now set up search
int depthPhase2 = 1;
int n = depthPhase1;
bool busy = false;
po[depthPhase1] = 0;
ax[depthPhase1] = 0;
minDistPhase2[n + 1] = 1; // else failure for depthPhase2=1, n=0
// +++++++++++++++++++ end initialization +++++++++++++++++++++++++++++++++
do
{
do
{
if ((depthPhase1 + depthPhase2 - n > minDistPhase2[n + 1]) && !busy)
{
if (ax[n] == 0 || ax[n] == 3) // Initialize next move
{
ax[++n] = 1;
po[n] = 2;
}
else
{
ax[++n] = 0;
po[n] = 1;
}
}
else if ((ax[n] == 0 || ax[n] == 3) ? (++po[n] > 3) : ((po[n] = po[n] + 2) > 3))
{
do
{ // increment axis
if (++ax[n] > 5)
{
if (n == depthPhase1)
{
if (depthPhase2 >= maxDepthPhase2)
{
return(-1);
}
else
{
depthPhase2++;
ax[n] = 0;
po[n] = 1;
busy = false;
break;
}
}
else
{
n--;
busy = true;
break;
}
}
else
{
if (ax[n] == 0 || ax[n] == 3)
{
po[n] = 1;
}
else
{
po[n] = 2;
}
busy = false;
}
} while (n != depthPhase1 && (ax[n - 1] == ax[n] || ax[n - 1] - 3 == ax[n]));
}
else
{
busy = false;
}
} while (busy);
// +++++++++++++ compute new coordinates and new minDist ++++++++++
mv = 3 * ax[n] + po[n] - 1;
URFtoDLF[n + 1] = CoordCubeBuildTables.URFtoDLF_Move[URFtoDLF[n], mv];
FRtoBR[n + 1] = CoordCubeBuildTables.FRtoBR_Move[FRtoBR[n], mv];
parity[n + 1] = CoordCubeBuildTables.parityMove[parity[n]][mv];
URtoDF[n + 1] = CoordCubeBuildTables.URtoDF_Move[URtoDF[n], mv];
minDistPhase2[n + 1] = Math.Max(CoordCubeBuildTables.getPruning(CoordCubeBuildTables.Slice_URtoDF_Parity_Prun, (CoordCubeBuildTables.N_SLICE2 * URtoDF[n + 1] + FRtoBR[n + 1]) * 2 + parity[n + 1]), CoordCubeBuildTables.getPruning(CoordCubeBuildTables.Slice_URFtoDLF_Parity_Prun, (CoordCubeBuildTables.N_SLICE2 * URFtoDLF[n + 1] + FRtoBR[n + 1]) * 2 + parity[n + 1]));
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
} while (minDistPhase2[n + 1] != 0);
return(depthPhase1 + depthPhase2);
}
/**
* Computes the solver string for a given cube.
*
* @param facelets
* is the cube definition string, see {@link Facelet} for the format.
*
* @param 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.
*
*@param 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.
*
* @param useSeparator
* determines if a " . " separates the phase1 and phase2 parts of the solver string like in F' R B R L2 F .
* U2 U D for example.<br>
* @return The solution string or an error code:<br>
* Error 1: There is not exactly one facelet of each colour<br>
* Error 2: Not all 12 edges exist exactly once<br>
* Error 3: Flip error: One edge has to be flipped<br>
* Error 4: Not all corners exist exactly once<br>
* Error 5: Twist error: One corner has to be twisted<br>
* Error 6: Parity error: Two corners or two edges have to be exchanged<br>
* Error 7: No solution exists for the given maxDepth<br>
* Error 8: Timeout, no solution within given time
*/
public static string solution(string facelets, out string info, int maxDepth = 50, long timeOut = 6000, bool useSeparator = false, bool buildTables = false)
{
info = "Warning, this solution builds tables at run time which is very slow. This will find a solution, however it is reccomended to use the K_SearchRunTime class only to create a local copy of the tables, then use the K_Search class to search for solutions instead.";
if (facelets == "UUUUUUUUURRRRRRRRRFFFFFFFFFDDDDDDDDDLLLLLLLLLBBBBBBBBB")
{
return("");
}
int s;
// +++++++++++++++++++++check for wrong input +++++++++++++++++++++++++++++
int[] count = new int[6];
try
{
for (int i = 0; i < 54; i++)
{
count[(int)CubeColor.Parse(typeof(CubeColor), facelets.Substring(i, 1))]++;
}
}
catch (Exception)
{
return("Error 1");
}
for (int i = 0; i < 6; i++)
{
if (count[i] != 9)
{
return("Error 1");
}
}
FaceCube fc = new FaceCube(facelets);
CubieCube cc = fc.toCubieCube();
if ((s = cc.verify()) != 0)
{
return("Error " + Math.Abs(s));
}
// +++++++++++++++++++++++ initialization +++++++++++++++++++++++++++++++++
CoordCubeBuildTables c = new CoordCubeBuildTables(cc, buildTables);
//return "lol";
po[0] = 0;
ax[0] = 0;
flip[0] = c.flip;
twist[0] = c.twist;
parity[0] = c.parity;
slice[0] = c.FRtoBR / 24;
URFtoDLF[0] = c.URFtoDLF;
FRtoBR[0] = c.FRtoBR;
URtoUL[0] = c.URtoUL;
UBtoDF[0] = c.UBtoDF;
minDistPhase1[1] = 1; // else failure for depth=1, n=0
int mv = 0, n = 0;
bool busy = false;
int depthPhase1 = 1;
long tStart = DateTimeHelper.CurrentUnixTimeMillis();
// +++++++++++++++++++ Main loop ++++++++++++++++++++++++++++++++++++++++++
do
{
do
{
if ((depthPhase1 - n > minDistPhase1[n + 1]) && !busy)
{
if (ax[n] == 0 || ax[n] == 3) // Initialize next move
{
ax[++n] = 1;
}
else
{
ax[++n] = 0;
}
po[n] = 1;
}
else if (++po[n] > 3)
{
do
{ // increment axis
if (++ax[n] > 5)
{
if (DateTimeHelper.CurrentUnixTimeMillis() - tStart > timeOut << 10)
{
return("Error 8");
}
if (n == 0)
{
if (depthPhase1 >= maxDepth)
{
return("Error 7");
}
else
{
depthPhase1++;
ax[n] = 0;
po[n] = 1;
busy = false;
break;
}
}
else
{
n--;
busy = true;
break;
}
}
else
{
po[n] = 1;
busy = false;
}
} while (n != 0 && (ax[n - 1] == ax[n] || ax[n - 1] - 3 == ax[n]));
}
else
{
busy = false;
}
} while (busy);
// +++++++++++++ compute new coordinates and new minDistPhase1 ++++++++++
// if minDistPhase1 =0, the H subgroup is reached
mv = 3 * ax[n] + po[n] - 1;
flip[n + 1] = CoordCubeBuildTables.flipMove[flip[n], mv];
twist[n + 1] = CoordCubeBuildTables.twistMove[twist[n], mv];
slice[n + 1] = CoordCubeBuildTables.FRtoBR_Move[slice[n] * 24, mv] / 24;
minDistPhase1[n + 1] = Math.Max(CoordCubeBuildTables.getPruning(CoordCubeBuildTables.Slice_Flip_Prun, CoordCubeBuildTables.N_SLICE1 * flip[n + 1] + slice[n + 1]), CoordCubeBuildTables.getPruning(CoordCubeBuildTables.Slice_Twist_Prun, CoordCubeBuildTables.N_SLICE1 * twist[n + 1] + slice[n + 1]));
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
if (minDistPhase1[n + 1] == 0 && n >= depthPhase1 - 5)
{
minDistPhase1[n + 1] = 10; // instead of 10 any value >5 is possible
if (n == depthPhase1 - 1 && (s = totalDepth(depthPhase1, maxDepth)) >= 0)
{
if (s == depthPhase1 || (ax[depthPhase1 - 1] != ax[depthPhase1] && ax[depthPhase1 - 1] != ax[depthPhase1] + 3))
{
return(useSeparator ? solutionToString(s, depthPhase1) : solutionToString(s));
}
}
}
} while (true);
}
