COROLLARY 9. An m • n (0, 1)-matrix specified by its f nonzero entries can be
tested for circular ones in O(m + n + f) steps.
Proof. By Lemma 8 the computation of M c is within the desired time bound.
The number of edges in M c is f' ~ 2f which is O(f). The rest of the work is just
the consecutive ones test so the total work is O(m + n + f). |
There are a number of generalizations for the consecutive ones property, including
some NP-complete problems associated with finding matrices which approximate
these properties. Further related results are surveyed in [3].