int
sm_col_dominance(sm_matrix *A, int *weight)
{
register sm_row *prow;
register sm_col *pcol, *pcol1;
register sm_element *p;
sm_row *least_row;
sm_col *next_col;
int colcnt;
colcnt = A->ncols;
/* Check each column against all other columns */
for(pcol = A->first_col; pcol != 0; pcol = next_col) {
next_col = pcol->next_col;
/* Check all rows to find the one with fewest elements */
least_row = sm_get_row(A, pcol->first_row->row_num);
for(p = pcol->first_row->next_row; p != 0; p = p->next_row) {
prow = sm_get_row(A, p->row_num);
if (prow->length < least_row->length) {
least_row = prow;
}
}
/* Only check for containment against columns in this row */
for(p = least_row->first_col; p != 0; p = p->next_col) {
pcol1 = sm_get_col(A, p->col_num);
if (weight != 0 && weight[pcol1->col_num] > weight[pcol->col_num])
continue;
if ((pcol1->length > pcol->length) ||
(pcol1->length == pcol->length &&
pcol1->col_num > pcol->col_num)) {
if (sm_col_contains(pcol, pcol1)) {
sm_delcol(A, pcol->col_num);
break;
}
}
}
}
return colcnt - A->ncols;
}
int
sm_row_dominance(sm_matrix *A)
{
register sm_row *prow, *prow1;
register sm_col *pcol, *least_col;
register sm_element *p, *pnext;
int rowcnt;
rowcnt = A->nrows;
/* Check each row against all other rows */
for(prow = A->first_row; prow != 0; prow = prow->next_row) {
/* Among all columns with a 1 in this row, choose smallest */
least_col = sm_get_col(A, prow->first_col->col_num);
for(p = prow->first_col->next_col; p != 0; p = p->next_col) {
pcol = sm_get_col(A, p->col_num);
if (pcol->length < least_col->length) {
least_col = pcol;
}
}
/* Only check for containment against rows in this column */
for(p = least_col->first_row; p != 0; p = pnext) {
pnext = p->next_row;
prow1 = sm_get_row(A, p->row_num);
if ((prow1->length > prow->length) ||
(prow1->length == prow->length &&
prow1->row_num > prow->row_num)) {
if (sm_row_contains(prow, prow1)) {
sm_delrow(A, prow1->row_num);
}
}
}
}
return rowcnt - A->nrows;
}
static int
visit_col(sm_matrix *A, sm_col *pcol, int *rows_visited, int *cols_visited)
{
sm_element *p;
sm_row *prow;
if (! pcol->flag) {
pcol->flag = 1;
(*cols_visited)++;
if (*cols_visited == A->ncols) {
return 1;
}
for(p = pcol->first_row; p != 0; p = p->next_row) {
prow = sm_get_row(A, p->row_num);
if (! prow->flag) {
if (visit_row(A, prow, rows_visited, cols_visited)) {
return 1;
}
}
}
}
return 0;
}
