Module: ppl/ppl Branch: sparse_matrices Commit: 343524886abe52d344037a76b186c913eec2f8d4 URL: http://www.cs.unipr.it/git/gitweb.cgi?p=ppl/ppl.git;a=commit;h=343524886abe5...

Author: Marco Poletti poletti.marco@gmail.com Date: Wed Sep 15 11:32:27 2010 +0200

MIP_Problem: use a hint iterator for insertions in working_cost, in process_pending_constraints().

---

src/MIP_Problem.cc | 11 ++++++++--- 1 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/MIP_Problem.cc b/src/MIP_Problem.cc index 1b54d00..58c2112 100644 --- a/src/MIP_Problem.cc +++ b/src/MIP_Problem.cc @@ -842,12 +842,16 @@ PPL::MIP_Problem::process_pending_constraints() { // constraint, will enter the base and will have coefficient -1 in // the cost function.

+ // This is used as a hint for insertions in working_cost. + working_cost_type::iterator cost_itr = working_cost.end(); + // First go through nonpending constraints that became unfeasible // due to re-merging of split variables. for (dimension_type i = 0; i < unfeasible_tableau_rows_size; ++i) { tableau[unfeasible_tableau_rows[i]].find_create(artificial_index, Coefficient_one()); - working_cost[artificial_index] = -1; + cost_itr = working_cost.find_create(cost_itr, artificial_index); + *cost_itr = -1; base[unfeasible_tableau_rows[i]] = artificial_index; ++artificial_index; } @@ -858,7 +862,8 @@ PPL::MIP_Problem::process_pending_constraints() { if (worked_out_row[i]) continue; tableau[i].find_create(artificial_index, Coefficient_one()); - working_cost[artificial_index] = -1; + cost_itr = working_cost.find_create(cost_itr, artificial_index); + *cost_itr = -1; base[i] = artificial_index; ++artificial_index; } @@ -868,7 +873,7 @@ PPL::MIP_Problem::process_pending_constraints() { // Set the extra-coefficient of the cost functions to record its sign. // This is done to keep track of the possible sign's inversion. const dimension_type last_obj_index = working_cost.size() - 1; - working_cost[last_obj_index] = 1; + working_cost.find_create(cost_itr, last_obj_index, Coefficient_one());

// Express the problem in terms of the variables in base. {