/// Print solution
virtual void
print(std::ostream& os) const {
os << "\tNumber of Queens: " << q << std::endl;
os << "\tBoard: " << b << std::endl;
if (b.assigned()) {
// Print a nice board
bool* placed = new bool[n*n];
for (int i=0; i<n*n; i++)
placed[i] = false;
for (int i=0; i<n*n; i++)
placed[b[i].val()] = true;
for (int j=0; j<n; j++) {
std::cout << "\t\t";
for (int i=0; i<n; i++)
std::cout << (placed[xy(i,j)] ? 'Q' : '.') << ' ';
std::cout << std::endl;
}
delete [] placed;
}
os << std::endl;
}
