%
% Filename: zerosum.mzn
% Usage:
% > minizinc -a --soln-sep "" --search-complete-msg "" -D "n=5;" zerosum.mzn | awk 'NF' >temp1.txt
% > awk 'BEGIN{print "[\\"}; END{print "[]];"}; {print $0 ",\\"};' temp1.txt >temp2.txt
% > gp -qf -s 256000000 lexsort.gp > temp3.txt
% > awk -f array.awk -v rows=3 temp3.txt >sol5.txt
% > cat lexsort.gp
/*
{
a = read("temp2.txt"); b = vecsort(a, lex);
for (i=1, #b, my(len = #b[i]); if (!len, next());
  for(j=1, len-1, print1(b[i][j], " ")); print(b[i][len]));
quit(0);
}
*/
% > cat array.awk
/*
{
    size = split($0, a); cols = size/rows;
    print NR;
    for(i = 0; i < rows; ++i) {
        for(j = 0; j < cols-1; ++j) printf("%2d ", a[i*cols+j+1]);
        printf("%2d\n", a[(i+1)*cols]);
    }
}
*/
%
% see also http://www.minizinc.org, http://pari.math.u-bordeaux.fr
%

include "globals.mzn";
int: n;
int: m = 3;

array[1..m, 1..2*n+1] of var -n..n: x;

constraint forall([alldifferent([x[i,j] | j in 1..2*n+1]) | i in 1..m]);
constraint forall([sum([x[i,j] | i in 1..m]) == 0 | j in 1..2*n+1]);
constraint forall([x[1,i] ==  -n-1+i | i in 1..2*n+1]);

solve satisfy;

output [show(x)];