include "alldifferent.mzn"; int: n; array[1..n] of var 1..n: y; % 每个数值的位置 array[1..n-1] of var 1..n-1: v; % 差值i的位置 constraint alldifferent(y); constraint alldifferent(v); constraint forall(i,j in 1..n where i < j)( (y[i] - y[j] = 1 -> v[j-i] = y[j]) /\ (y[j] - y[i] = 1 -> v[j-i] = y[i]) ); constraint abs(y[1] - y[n]) = 1 /\ v[n-1] = min(y[1], y[n]); solve :: int_search(y, first_fail, indomain_min, complete) satisfy; output [ "x = [",] ++ [ show(i) ++ if j == n then "]\n;" else ", " endif | j in 1..n, i in 1..n where j == fix(y[i]) ];