public void unpack(int c) {
int l = 1;
for (int i = 0; i < comb.a.length; i++) // count number of different orientations
if ((~active & 1 << i) != 0) l *= 3;
if ((active & 0xFF) != 0) { // some orientations are not set
comb.combUnpack(c / l); // unpack combination
c %= l; // let it be only orientations
for (int i = comb.a.length - 1; i >= 0; i--) {
if (comb.a[i] != 0) {
comb.a[i] = c % 3 + 1;
c /= 3;
}
}
} else { // all orientations are set
int t = 0;
l /= 3; // one corner orientation is given
comb.combUnpack(c / l);
c %= l;
for (int i = comb.a.length - 2; i >= 0; i--) {
comb.a[i] = c % 3 + 1;
t += c % 3;
c /= 3;
}
comb.a[comb.a.length - 1] = (3 - (t % 3)) % 3 + 1; // set the last orientation
}
}
/**
* By redefining of start() and startLength(), solving to the specified state can be done.
* position = 0, 1,..., startLength() - 1
*/
public int start(int pos) {
int p1 = 0;
int o1 = 0;
for (int i = 0; i < comb.a.length; i++) {
if ((active >> 8 & 1 << i) != 0) { // unspecified position
p1++;
if ((active & 1 << i) == 0) // specified orientation
o1++;
}
}
Comb c = new Comb(p1, o1);
c.combUnpack(pos);
for (int i = 0, j = 0; i < comb.a.length; i++) {
if ((active >> 8 & 1 << i) != 0) // unspecified position
comb.a[i] = c.a[j++];
else if ((active & 1 << i) == 0) // specified position and orientation
comb.a[i] = 1;
else // specified position, unspecified orientation
comb.a[i] = 0;
}
return pack();
}