Solution to Advent Of Code Day 04 with MiniZinc (CLP)

AoC-day04.mzn

array [1..6] of var 0..9: pass;

int:lower = 264793;
int:upper = 803935;

predicate in_range(array [1..6] of var 0..9: a) = 
  let { 
    var int: n = a[1] * 100000 +   
        a[2] * 10000 + 
        a[3] * 1000 + 
        a[4] * 100 + 
        a[5] * 10 + 
        a[6];
   } in (lower <= n /\ n <= upper) == true;

constraint exists([pass[i] == pass[j] | i,j in 1..6 where i=j+1]);
constraint forall([pass[i] >= pass[j] | i,j in 1..6 where i=j+1]);
constraint in_range(pass);

solve satisfy;

% To obtain all answers execute with flag '-a'
%   $> minizinc --solver gecode -a day04.mzn | grep pass | wc -l