Group diagnostic tags without dynamic allocation

typedef struct { byte text[17]; } diag_tag_t;

typedef struct {
  byte unsigned len;
  byte unsigned letter_count[26];
} tag_signature_t;

function automatic bit build_signature(
  input diag_tag_t tag,
  output tag_signature_t signature
);
  // Implement here: build_signature.
endfunction

function automatic bit same_signature(
  input tag_signature_t left,
  input tag_signature_t right
);
  // Implement here: same_signature.
endfunction

// ref is required for the output aggregates: an output formal is copy-out and
// cannot preserve its caller value on failure. This corrected interface makes
// the stated all-or-nothing contract implementable.
function automatic bit group_tags(
  input diag_tag_t tags[32],
  input int unsigned count,
  ref byte unsigned order[32],
  ref byte unsigned group_start[33],
  ref int unsigned group_count
);
  tag_signature_t signatures[32];
  byte unsigned staged_order[32];
  byte unsigned staged_start[33];
  bit assigned[32];
  int unsigned write_index = 0;
  int unsigned staged_group_count = 0;
  // Implement here: validate, group by stable signatures, and publish staged outputs.
endfunction