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Update Network Simplex implementation

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Anh-Dung Phan 2013-10-28 18:29:14 -07:00
parent d78d22deb6
commit 906bbb4eeb
4 changed files with 200 additions and 152 deletions
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24
src/smt/theory_diff_logic_def.h
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@ -1016,34 +1016,26 @@ bool theory_diff_logic<Ext>::maximize(theory_var v) {
// m_graph as well.
dl_graph<GExt> g;
vector<dl_edge<GExt> > const& es = m_graph.get_all_edges();
dl_var offset = m_graph.get_num_edges();
for (unsigned i = 0; i < es.size(); ++i) {
dl_edge<GExt> const & e = es[i];
if (e.is_enabled()) {
g.enable_edge(g.add_edge(e.get_source(), e.get_target(), e.get_weight(), e.get_explanation()));
g.enable_edge(g.add_edge(e.get_target() + offset, e.get_source() + offset, e.get_weight(), e.get_explanation()));
}
}
// Objective coefficients now become costs
vector<fin_numeral> base_costs, aux_costs;
// Objective coefficients now become balances
vector<fin_numeral> balances;
for (unsigned i = 0; i < objective.size(); ++i) {
fin_numeral cost(objective[i].second);
base_costs.push_back(cost);
aux_costs.push_back(-cost);
fin_numeral balance(objective[i].second);
balances.push_back(balance);
}
vector<fin_numeral> costs;
costs.append(base_costs);
costs.append(aux_costs);
network_flow<GExt> net_flow(g, costs);
network_flow<GExt> net_flow(g, balances);
bool is_optimal = net_flow.min_cost();
if (is_optimal) {
numeral objective_value;
vector<numeral> flows;
net_flow.get_optimal_solution(objective_value, flows);
m_objective_value = objective_value.get_rational();
// TODO: return the model of the optimal solution
vector<numeral> potentials;
m_objective_value = net_flow.get_optimal_solution(potentials, true);
// TODO: return the model of the optimal solution from potential
}
return is_optimal;
}