annotation bitdomain(int:nwords); include "alldifferent.mzn"; int: n; array [1..n] of var 1..n: q :: bitdomain(n div 32); constraint alldifferent(q) :: domain; constraint alldifferent([ q[i] + i | i in 1..n]) :: domain; constraint alldifferent([ q[i] - i | i in 1..n]) :: domain; ann: search_ann; solve :: search_ann satisfy; output [ if fix(q[j]) == i then "Q" else "." endif ++ if j == n then "\n" else "" endif | i,j in 1..n]