strqueue_sort_cmp
solv_sort(q->str, q->nstr, sizeof(*q->str), strqueue_sort_cmp, 0);
if (!j || strqueue_sort_cmp(q->str + i, q->str + j - 1, 0) != 0)
int r = strqueue_sort_cmp(sq1->str + i, sq2->str + j, 0);