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Fix bugs on candidate list pivot rule

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This commit is contained in:
Anh-Dung Phan 2013-11-11 18:23:21 -08:00
parent 0d6ffe6b31
commit 66eda866ca
2 changed files with 57 additions and 43 deletions
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76
src/smt/network_flow.h
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@ -156,24 +156,29 @@ namespace smt {
private:
edge_id m_next_edge;
svector<edge_id> m_candidates;
unsigned num_candidates;
unsigned m_num_candidates;
unsigned m_minor_step;
unsigned m_current_length;
static const unsigned NUM_CANDIDATES = 10;
static const unsigned MINOR_STEP_LIMIT = 5;
public:
candidate_list_pivot(graph & g, vector<numeral> & potentials,
svector<edge_state> & states, edge_id & enter_id) :
pivot_rule_impl(g, potentials, states, enter_id),
m_next_edge(0),
num_candidates(NUM_CANDIDATES),
m_candidates(num_candidates) {
m_minor_step(0),
m_current_length(0),
m_num_candidates(NUM_CANDIDATES),
m_candidates(m_num_candidates) {
}
bool choose_entering_edge() {
if (m_candidates.empty()) {
if (m_current_length == 0 || m_minor_step == MINOR_STEP_LIMIT) {
// Build the candidate list
unsigned num_edges = m_graph.get_num_edges();
numeral max = numeral::zero();
unsigned count = 0;
m_current_length = 0;
for (unsigned i = m_next_edge; i < m_next_edge + num_edges; ++i) {
edge_id id = (i >= num_edges) ? i - num_edges : i;
node src = m_graph.get_source(id);
@ -181,16 +186,18 @@ namespace smt {
if (m_states[id] != BASIS) {
numeral cost = m_potentials[src] - m_potentials[tgt] - m_graph.get_weight(id);
if (cost.is_pos()) {
m_candidates[count++] = id;
m_candidates[m_current_length] = id;
++m_current_length;
if (cost > max) {
max = cost;
m_enter_id = id;
}
}
if (count >= num_candidates) break;
if (m_current_length >= m_num_candidates) break;
}
}
m_next_edge = m_enter_id;
m_minor_step = 1;
if (max.is_pos()) {
TRACE("network_flow", {
tout << "Found entering edge " << m_enter_id << " between node ";
@ -202,36 +209,37 @@ namespace smt {
TRACE("network_flow", tout << "Found no entering edge...\n";);
return false;
}
else {
numeral max = numeral::zero();
unsigned last = m_candidates.size();
for (unsigned i = 0; i < last; ++i) {
edge_id id = m_candidates[i];
node src = m_graph.get_source(id);
node tgt = m_graph.get_target(id);
if (m_states[id] != BASIS) {
numeral cost = m_potentials[src] - m_potentials[tgt] - m_graph.get_weight(id);
if (cost > max) {
max = cost;
m_enter_id = id;
}
// Remove stale candidates
if (!cost.is_pos()) {
m_candidates[i] = m_candidates[--last];
}
++m_minor_step;
numeral max = numeral::zero();
for (unsigned i = 0; i < m_current_length; ++i) {
edge_id id = m_candidates[i];
node src = m_graph.get_source(id);
node tgt = m_graph.get_target(id);
if (m_states[id] != BASIS) {
numeral cost = m_potentials[src] - m_potentials[tgt] - m_graph.get_weight(id);
if (cost > max) {
max = cost;
m_enter_id = id;
}
// Remove stale candidates
if (!cost.is_pos()) {
--m_current_length;
m_candidates[i] = m_candidates[m_current_length];
--i;
}
}
if (max.is_pos()) {
TRACE("network_flow", {
tout << "Found entering edge " << m_enter_id << " between node ";
tout << m_graph.get_source(m_enter_id) << " and node " << m_graph.get_target(m_enter_id);
tout << " with reduced cost = " << max << "...\n";
});
return true;
}
TRACE("network_flow", tout << "Found no entering edge...\n";);
return false;
}
if (max.is_pos()) {
TRACE("network_flow", {
tout << "Found entering edge " << m_enter_id << " between node ";
tout << m_graph.get_source(m_enter_id) << " and node " << m_graph.get_target(m_enter_id);
tout << " with reduced cost = " << max << "...\n";
});
return true;
}
TRACE("network_flow", tout << "Found no entering edge...\n";);
return false;
};
};