private static void print(IntVar[] vars, Domain[] solution) {
for (int i = 0; i < solution.length; i += size) {
String[] names = new String[size];
for (int j = 0; j < size; ++j) {
IntDomain x = (IntDomain) solution[i + j];
int idx = x.getElementAt(0);
names[idx] = vars[i + j].id;
}
for (String name : names) {
System.out.printf("%11s ", name);
}