Challenge 58 #2

multi order(@H, @T) {
   my %p = @H Z[=>] @T;
   my @p = %p.pairs.sort(*.key <=> *.key);

   multi order(@a, $i where { @a[$i]:!exists }, 0,  $h) { @a[$i] = $h }
   multi order(@a, $i where { @a[$i]:!exists }, $t, $h) { order @a, $i + 1, $t - 1, $h }
   multi order(@a, $i where { @a[$i]:exists  }, $t, $h) { order @a, $i + 1, $t, $h }
   my @a;
   order @a, 0, .value, .key for @p;
   say @a
}
order 
    (27, 21, 37,  4, 19, 52, 23, 64,  1,  7, 51, 17, 24, 50,  3,  2,
        34, 40, 47, 20,  8, 56, 14, 16, 42, 38, 62, 53, 31, 41, 55, 59,
        48, 12, 32, 61,  9, 60, 46, 26, 58, 25, 15, 36, 11, 44, 63, 28,
        5, 54, 10, 49, 57, 30, 29, 22, 35, 39, 45, 43, 18,  6, 13, 33),
    ( 6, 41,  1, 49, 38, 12,  1,  0, 58, 47,  4, 17, 26,  1, 61, 12,
        29,  3,  4, 11, 45,  1, 32,  5,  9, 19,  1,  4, 28, 12,  2,  2,
        13, 18, 19,  3,  4,  1, 10, 16,  4,  3, 29,  5, 49,  1,  1, 24,
        2,  1, 38,  7,  7, 14, 35, 25,  0,  5,  4, 19, 10, 13,  4, 12)