mirrors/z3
3
0
Fork 0
mirror of https://github.com/Z3Prover/z3 synced 2025-04-23 17:15:31 +00:00
Code Activity

adding simplex

Browse source 
Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2014-02-12 20:20:52 -08:00
parent a594597906
commit 51cb63b6c0
8 changed files with 42 additions and 13 deletions
Download patch file Download diff file Expand all files Collapse all files

2
src/math/simplex/simplex_def.h
View file

@ -161,6 +161,7 @@ namespace simplex {
template<typename Ext>
lbool simplex<Ext>::make_feasible() {
TRACE("simplex", tout << "\n";);
m_left_basis.reset();
m_infeasible_var = null_var;
unsigned num_iterations = 0;
@ -168,6 +169,7 @@ namespace simplex {
var_t v = null_var;
SASSERT(well_formed());
while ((v = select_var_to_fix()) != null_var) {
TRACE("simplex", tout << "v" << v << "\n";);
if (m_cancel || num_iterations > m_max_iterations) {
return l_undef;
}

26
src/math/simplex/sparse_matrix.h
View file

@ -106,8 +106,9 @@ namespace simplex {
svector<col_entry> m_entries;
unsigned m_size;
int m_first_free_idx;
mutable unsigned m_refs;
column():m_size(0), m_first_free_idx(-1) {}
column():m_size(0), m_first_free_idx(-1), m_refs(0) {}
unsigned size() const { return m_size; }
unsigned num_entries() const { return m_entries.size(); }
void reset();
@ -160,9 +161,9 @@ namespace simplex {
class row_iterator {
friend sparse_matrix;
unsigned m_curr;
_row & m_row;
_row & m_row;
void move_to_used() {
while (m_curr < m_row.m_entries.size() &&
while (m_curr < m_row.num_entries() &&
m_row.m_entries[m_curr].is_dead()) {
++m_curr;
}
@ -173,7 +174,7 @@ namespace simplex {
move_to_used();
}
else {
m_curr = m_row.m_entries.size();
m_curr = m_row.num_entries();
}
}
public:
@ -192,25 +193,32 @@ namespace simplex {
class col_iterator {
friend sparse_matrix;
unsigned m_curr;
column const& m_col;
unsigned m_curr;
column const& m_col;
vector<_row> const& m_rows;
void move_to_used() {
while (m_curr < m_col.m_entries.size() && m_col.m_entries[m_curr].is_dead()) {
while (m_curr < m_col.num_entries() && m_col.m_entries[m_curr].is_dead()) {
++m_curr;
}
}
col_iterator(column const& c, vector<_row> const& r, bool begin):
m_curr(0), m_col(c), m_rows(r) {
++m_col.m_refs;
if (begin) {
move_to_used();
}
else {
m_curr = m_col.m_entries.size();
m_curr = m_col.num_entries();
}
}
public:
row get_row() { return row(m_col.m_entries[m_curr].m_row_id); }
~col_iterator() {
--m_col.m_refs;
}
row get_row() {
return row(m_col.m_entries[m_curr].m_row_id);
}
row_entry const& get_row_entry() {
col_entry const& c = m_col.m_entries[m_curr];
int row_id = c.m_row_id;

2
src/math/simplex/sparse_matrix_def.h
View file

@ -200,7 +200,7 @@ namespace simplex {
*/
template<typename Ext>
inline void sparse_matrix<Ext>::column::compress_if_needed(vector<_row> & rows) {
if (size() * 2 < num_entries()) {
if (size() * 2 < num_entries() && m_refs == 0) {
compress(rows);
}
}