%
% Filename: dyck4.mzn
% Usage:
% minizinc -a --soln-sep "" --search-complete-msg "" -D "n=4;" dyck4.mzn 2>/dev/null | awk 'NF' | sort
%
% see also http://www.minizinc.org
%

include "globals.mzn";

int: n;
array[int] of string: sym = ["R", "L"];

array[1..4*n] of var {-1,1}: x;
array[1..4*n] of var 0..n: height;

constraint height[1] == x[1];
constraint forall([height[k] - height[k-1] == x[k] | k in 2..4*n]);
constraint height[4*n] == 0;
constraint exists([height[k] == n | k in 1..4*n]);

solve satisfy;

output [sym[1 + (1+fix(x[i])) div 2]| i in 1..4*n];