include "globals.mzn";

int: order; % this is called the length in the new problem.

set of int: LEN = 0..order*order;
array[1..order] of var LEN: marks;
int: ndiffs = order*(order-1) div 2;
array[1..ndiffs] of var LEN: diffs =
  [marks[j] - marks[i] | i in 1..order, j in i+1..order];

% Old Golomb constraints.
constraint increasing(marks) /\ marks[1] = 0 /\ alldifferent(diffs);
% Break symmetry (optimisation): First difference is smaller than last one.
constraint diffs[1] < diffs[ndiffs];

% Extra constraint: maximize obj s.th. diffs 1..obj appear.
var 0..ndiffs: obj;
constraint forall(d in 1..obj)(count(diffs, d) = 1);

solve :: int_search(marks, input_order, indomain_min, complete) maximize obj;
output ["\(show_int(-3, order)) \(show_int(-3, obj))"] ++ [" \(x)" | x in marks] ++ ["\n"];