#include "espresso.h"

pset do_sm_minimum_cover(pset_family A) {
    sm_matrix *M;
    sm_row *sparse_cover;
    sm_element *pe;
    pset cover;
    int i, base, rownum;
    unsigned val;
    pset last, p;

    M = sm_alloc();
    rownum = 0;
    foreach_set(A, last, p) {
        foreach_set_element(p, i, val, base) {
            (void)sm_insert(M, rownum, base);
        }
        rownum++;
    }

    sparse_cover = sm_minimum_cover(M, NIL(int), 1);
    sm_free(M);

    cover = set_new(A->sf_size);
    sm_foreach_row_element(sparse_cover, pe) {
        set_insert(cover, pe->col_num);
    }
    sm_row_free(sparse_cover);

    return cover;
}
