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Extract GTSP_find_exact_subtour_elimination_cuts_1

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master
Alinson S. Xavier 11 years ago
parent 2a2fd6713b
commit 45946b235d
1 changed files with 342 additions and 325 deletions
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src/gtsp.c
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@ -385,20 +385,22 @@ int GTSP_add_subtour_elimination_cut_3(
return rval;
}
int GTSP_build_flow_digraph(struct GTSP *data, double *x, struct Graph *digraph, double *capacities)
int GTSP_build_flow_digraph(
struct GTSP *data, double *x, struct Graph *digraph, double *capacities)
{
int rval = 0;
int *digraph_edges = 0;
struct Graph *graph = data->graph;
int node_count = graph->node_count;
int node_count = data->graph->node_count;
struct Graph *graph = data->graph;
int digraph_node_count = node_count + data->cluster_count + 1;
int digraph_edge_count = 4 * graph->edge_count + 2 * graph->node_count +
2 * data->cluster_count;
int digraph_node_count = node_count + data->cluster_count + 1;
digraph_edges = (int *) malloc(2 * digraph_edge_count * sizeof(int));
abort_if(!digraph_edges, "could not allocate digraph_edges");
// Create four directed edges for each edge of the original graph
int ke = 0;
@ -468,60 +470,38 @@ int GTSP_build_flow_digraph(struct GTSP *data, double *x, struct Graph *digraph,
digraph->edges[i + 1].reverse = &digraph->edges[i];
}
CLEANUP:
if (digraph_edges) free(digraph_edges);
return rval;
}
int GTSP_find_exact_subtour_elimination_cuts(
struct LP *lp, struct GTSP *data, int *added_cuts_count)
int GTSP_find_exact_subtour_elimination_cuts_1(
struct LP *lp,
struct GTSP *data,
double *x,
struct Graph *digraph,
double *capacities,
int *added_cuts_count)
{
int rval = 0;
double *x = 0;
double *flow = 0;
double *capacities = 0;
struct Edge **cut_edges = 0;
double *flow = 0;
int *clusters = data->clusters;
struct Graph *graph = data->graph;
int node_count = graph->node_count;
int num_cols = LP_get_num_cols(lp);
x = (double *) malloc(num_cols * sizeof(double));
abort_if(!x, "could not allocate x");
rval = LP_get_x(lp, x);
abort_if(rval, "LP_get_x failed");
struct Graph digraph;
graph_init(&digraph);
int digraph_edge_count = 4 * graph->edge_count + 2 * graph->node_count +
2 * data->cluster_count;
int *clusters = data->clusters;
flow = (double *) malloc(digraph_edge_count * sizeof(double));
capacities = (double *) malloc(digraph_edge_count * sizeof(double));
cut_edges =
(struct Edge **) malloc(digraph_edge_count * sizeof(struct Edge *));
cut_edges = (struct Edge **) malloc(
digraph->edge_count * sizeof(struct Edge *));
flow = (double *) malloc(digraph->edge_count * sizeof(double));
abort_if(!flow, "could not allocate flow");
abort_if(!capacities, "could not allocate capacities");
abort_if(!cut_edges, "could not allocate cut_edges");
abort_if(!flow, "could not allocate flow");
rval = GTSP_build_flow_digraph(data, x, &digraph, capacities);
abort_if(rval, "GTSP_build_flow_digraph failed");
// Constraints (2.3)
{
int max_x_index = 0;
double max_x = DBL_MIN;
for (int i = 0; i < node_count; i++)
for (int i = 0; i < graph->node_count; i++)
{
struct Node *n = &graph->nodes[i];
if (x[n->index] > max_x)
@ -533,20 +513,22 @@ int GTSP_find_exact_subtour_elimination_cuts(
int i = max_x_index;
for (int j = 0; j < node_count; j++)
for (int j = 0; j < graph->node_count; j++)
{
if (i == j) continue;
if (clusters[i] == clusters[j]) continue;
if (x[i] + x[j] - 1 <= LP_EPSILON) continue;
struct Node *from = &digraph.nodes[i];
struct Node *to = &digraph.nodes[j];
struct Node *from = &digraph->nodes[i];
struct Node *to = &digraph->nodes[j];
double flow_value;
log_verbose("Calculating max flow from node %d to node %to\n",
from->index, to->index);
double flow_value;
rval = flow_find_max_flow(&digraph, capacities, from, to, flow,
rval = flow_find_max_flow(digraph, capacities, from, to, flow,
&flow_value);
abort_if(rval, "flow_find_max_flow failed");
@ -559,68 +541,7 @@ int GTSP_find_exact_subtour_elimination_cuts(
2 * (x[i] + x[j] - 1));
int cut_edges_count;
rval = get_cut_edges_from_marks(&digraph, &cut_edges_count,
cut_edges);
abort_if(rval, "get_cut_edges_from_marks failed");
log_verbose("Adding cut for i=%d j=%d, cut edges:\n", i, j);
int c = 0;
for (int k = 0; k < cut_edges_count / 2; k++)
{
int idx = cut_edges[k * 2]->index / 4;
if (idx > graph->edge_count) continue;
cut_edges[c++] = &graph->edges[idx];
log_verbose(" %d %d\n", cut_edges[c - 1]->from->index,
cut_edges[c - 1]->to->index);
}
rval = GTSP_add_subtour_elimination_cut(lp, graph, from, to,
cut_edges, c);
abort_if(rval, "GTSP_add_subtour_elimination_cut failed");
(*added_cuts_count)++;
if (*added_cuts_count > 10) goto CLEANUP;
}
}
// Constraints (2.2)
for (int i = 0; i < node_count; i++)
{
for (int j = 0; j < data->cluster_count; j++)
{
if (clusters[i] == j) continue;
if (x[i] < LP_EPSILON) continue;
struct Node *from = &digraph.nodes[i];
struct Node *to = &digraph.nodes[node_count + j];
// for (int k = 0; k < graph->node_count; k++)
// {
// struct Node *n = &graph->nodes[k];
// if (clusters[n->index] != clusters[i]) continue;
//
// int offset = 4 * graph->edge_count + 2 * k;
// capacities[offset] = 0;
// capacities[offset + 1] = 0;
// }
log_verbose("Calculating max flow from node %d to cluster %to\n", i,
j);
double flow_value;
rval = flow_find_max_flow(&digraph, capacities, from, to, flow,
&flow_value);
abort_if(rval, "flow_find_max_flow failed");
log_verbose(" %.2lf\n", flow_value);
if (flow_value >= 2 * x[i] - LP_EPSILON) continue;
log_verbose("violation: %.2lf >= %.2lf\n", flow_value, 2 * x[i]);
int cut_edges_count;
rval = get_cut_edges_from_marks(&digraph, &cut_edges_count,
cut_edges);
rval = get_cut_edges_from_marks(digraph, &cut_edges_count, cut_edges);
abort_if(rval, "get_cut_edges_from_marks failed");
log_verbose("Adding cut for i=%d j=%d, cut edges:\n", i, j);
@ -635,212 +556,308 @@ int GTSP_find_exact_subtour_elimination_cuts(
cut_edges[c - 1]->to->index);
}
rval = GTSP_add_subtour_elimination_cut_2(lp, graph, from, to,
cut_edges, c);
rval = GTSP_add_subtour_elimination_cut(lp, graph, from, to, cut_edges,
c);
abort_if(rval, "GTSP_add_subtour_elimination_cut failed");
for (int k = 0; k < graph->node_count; k++)
{
int offset = 4 * graph->edge_count + 2 * k;
capacities[offset] = 1e10;
capacities[offset + 1] = 1e10;
}
(*added_cuts_count)++;
if (*added_cuts_count > 10) goto CLEANUP;
}
}
// Constraints (2.1)
for (int i = 0; i < data->cluster_count; i++)
{
for (int j = i + 1; j < data->cluster_count; j++)
{
struct Node *from = &digraph.nodes[node_count + i];
struct Node *to = &digraph.nodes[node_count + j];
log_verbose("Calculating max flow from cluster %d to cluster %to\n",
i, j);
double flow_value;
rval = flow_find_max_flow(&digraph, capacities, from, to, flow,
&flow_value);
abort_if(rval, "flow_find_max_flow failed");
log_verbose(" %.2lf\n", flow_value);
if (flow_value >= 2 - LP_EPSILON) continue;
log_verbose("violation: %.2lf >= 2\n", flow_value);
int cut_edges_count;
rval = get_cut_edges_from_marks(&digraph, &cut_edges_count,
cut_edges);
abort_if(rval, "get_cut_edges_from_marks failed");
log_verbose("Adding cut for i=%d j=%d, cut edges:\n", i, j);
int c = 0;
for (int k = 0; k < cut_edges_count / 2; k++)
{
int idx = cut_edges[k * 2]->index / 4;
if (idx > graph->edge_count) continue;
cut_edges[c++] = &graph->edges[idx];
log_verbose(" %d %d\n", cut_edges[c - 1]->from->index,
cut_edges[c - 1]->to->index);
}
rval = GTSP_add_subtour_elimination_cut_3(lp, graph, from, to,
cut_edges, c);
abort_if(rval, "GTSP_add_subtour_elimination_cut3 failed");
(*added_cuts_count)++;
if (*added_cuts_count > 10) goto CLEANUP;
}
}
// subcluster
struct Node *root = &digraph.nodes[digraph.node_count - 1];
for (int e_index = 0; e_index < graph->edge_count; e_index++)
{
struct Edge *e = &graph->edges[e_index];
double x_e = x[node_count + e_index];
if (x_e < LP_EPSILON) continue;
struct Node *from = &digraph.nodes[e->from->index];
struct Node *to = &digraph.nodes[e->to->index];
if (x[from->index] > 1 - LP_EPSILON && x[to->index] > 1 - LP_EPSILON)
continue;
capacities[4 * e_index] = capacities[4 * e_index + 2] = 0;
int cluster_from_index = data->clusters[from->index];
int cluster_to_index = data->clusters[to->index];
for (int k = 0; k < data->cluster_count; k++)
{
if (cluster_from_index == k) continue;
if (cluster_to_index == k) continue;
int offset = 4 * graph->edge_count + 2 * node_count + 2 * k;
capacities[offset] = 1e10;
capacities[offset + 1] = 1e10;
}
for (int k = 0; k < graph->node_count; k++)
{
struct Node *n = &graph->nodes[k];
if (clusters[n->index] != cluster_from_index &&
clusters[n->index] != cluster_to_index)
continue;
int offset = 4 * graph->edge_count + 2 * k;
capacities[offset] = 0;
capacities[offset + 1] = 0;
}
// First direction
log_debug("Calculating max flow from (%d,%d) to root\n", from->index,
to->index);
double flow_value;
rval = flow_find_max_flow(&digraph, capacities, from, root, flow,
&flow_value);
abort_if(rval, "flow_find_max_flow failed");
log_debug(" %.2lf\n", flow_value);
if (flow_value + LP_EPSILON < x_e)
{
log_debug("violation: %.2lf > %.2lf\n", flow_value, x_e);
int cut_edges_count;
rval = get_cut_edges_from_marks(&digraph, &cut_edges_count,
cut_edges);
abort_if(rval, "get_cut_edges_from_marks failed");
log_debug("Adding cut for i=%d j=root, cut edges:\n", from->index);
int c = 0;
for (int k = 0; k < cut_edges_count / 2; k++)
{
int idx = cut_edges[k * 2]->index / 4;
if (idx == e_index) continue;
if (idx >= graph->edge_count) continue;
cut_edges[c++] = &graph->edges[idx];
log_debug(" %d %d\n", cut_edges[c - 1]->from->index,
cut_edges[c - 1]->to->index);
}
rval = GTSP_add_subcluster_cut(lp, graph, e, cut_edges, c);
abort_if(rval, "GTSP_add_subcluster_cut failed");
(*added_cuts_count)++;
if (*added_cuts_count > 10) goto CLEANUP;
} else
{
// Reverse direction
log_debug("Trying reverse edge:\n", to->index, from->index);
CLEANUP:
if (flow) free(flow);
if (cut_edges) free(cut_edges);
return rval;
}
rval = flow_find_max_flow(&digraph, capacities, to, root, flow,
&flow_value);
abort_if(rval, "flow_find_max_flow failed");
int GTSP_find_exact_subtour_elimination_cuts(
struct LP *lp, struct GTSP *data, int *added_cuts_count)
{
int rval = 0;
log_debug(" %.2lf\n", flow_value);
double *x = 0;
double *capacities = 0;
if (flow_value + LP_EPSILON < x_e)
{
log_debug("violation: %.2lf > %.2lf\n", flow_value, x_e);
struct Graph *graph = data->graph;
int cut_edges_count;
rval = get_cut_edges_from_marks(&digraph, &cut_edges_count,
cut_edges);
abort_if(rval, "get_cut_edges_from_marks failed");
int num_cols = LP_get_num_cols(lp);
x = (double *) malloc(num_cols * sizeof(double));
abort_if(!x, "could not allocate x");
log_debug("Adding cut for i=%d j=root, cut edges:\n",
from->index);
int c = 0;
for (int k = 0; k < cut_edges_count / 2; k++)
{
int idx = cut_edges[k * 2]->index / 4;
if (idx == e_index) continue;
if (idx >= graph->edge_count) continue;
rval = LP_get_x(lp, x);
abort_if(rval, "LP_get_x failed");
cut_edges[c++] = &graph->edges[idx];
log_debug(" %d %d\n", cut_edges[c - 1]->from->index,
cut_edges[c - 1]->to->index);
}
struct Graph digraph;
graph_init(&digraph);
rval = GTSP_add_subcluster_cut(lp, graph, e, cut_edges, c);
abort_if(rval, "GTSP_add_subcluster_cut failed");
int digraph_edge_count = 4 * graph->edge_count + 2 * graph->node_count +
2 * data->cluster_count;
(*added_cuts_count)++;
if (*added_cuts_count > 10) goto CLEANUP;
}
}
capacities = (double *) malloc(digraph_edge_count * sizeof(double));
abort_if(!capacities, "could not allocate capacities");
capacities[4 * e_index] = x_e;
capacities[4 * e_index + 2] = x_e;
rval = GTSP_build_flow_digraph(data, x, &digraph, capacities);
abort_if(rval, "GTSP_build_flow_digraph failed");
for (int k = 0; k < graph->node_count; k++)
{
int offset = 4 * graph->edge_count + 2 * k;
capacities[offset] = 1e10;
capacities[offset + 1] = 1e10;
}
rval = GTSP_find_exact_subtour_elimination_cuts_1(lp, data, x, &digraph,
capacities, added_cuts_count);
abort_if(rval, "GTSP_find_exact_subtour_elimination_cuts_1 failed");
for (int k = 0; k < data->cluster_count; k++)
{
int offset = 4 * graph->edge_count + 2 * graph->node_count;
capacities[offset + 2 * k] = 0;
capacities[offset + 2 * k + 1] = 0;
}
}
// // Constraints (2.2)
// for (int i = 0; i < node_count; i++)
// {
// for (int j = 0; j < data->cluster_count; j++)
// {
// if (clusters[i] == j) continue;
// if (x[i] < LP_EPSILON) continue;
//
// struct Node *from = &digraph.nodes[i];
// struct Node *to = &digraph.nodes[node_count + j];
//
//// for (int k = 0; k < graph->node_count; k++)
//// {
//// struct Node *n = &graph->nodes[k];
//// if (clusters[n->index] != clusters[i]) continue;
////
//// int offset = 4 * graph->edge_count + 2 * k;
//// capacities[offset] = 0;
//// capacities[offset + 1] = 0;
//// }
//
// log_verbose("Calculating max flow from node %d to cluster %to\n", i,
// j);
// double flow_value;
// rval = flow_find_max_flow(&digraph, capacities, from, to, flow,
// &flow_value);
// abort_if(rval, "flow_find_max_flow failed");
//
// log_verbose(" %.2lf\n", flow_value);
//
// if (flow_value >= 2 * x[i] - LP_EPSILON) continue;
//
// log_verbose("violation: %.2lf >= %.2lf\n", flow_value, 2 * x[i]);
//
// int cut_edges_count;
// rval = get_cut_edges_from_marks(&digraph, &cut_edges_count,
// cut_edges);
// abort_if(rval, "get_cut_edges_from_marks failed");
//
// log_verbose("Adding cut for i=%d j=%d, cut edges:\n", i, j);
// int c = 0;
// for (int k = 0; k < cut_edges_count / 2; k++)
// {
// int idx = cut_edges[k * 2]->index / 4;
// if (idx > graph->edge_count) continue;
//
// cut_edges[c++] = &graph->edges[idx];
// log_verbose(" %d %d\n", cut_edges[c - 1]->from->index,
// cut_edges[c - 1]->to->index);
// }
//
// rval = GTSP_add_subtour_elimination_cut_2(lp, graph, from, to,
// cut_edges, c);
// abort_if(rval, "GTSP_add_subtour_elimination_cut failed");
//
// for (int k = 0; k < graph->node_count; k++)
// {
// int offset = 4 * graph->edge_count + 2 * k;
// capacities[offset] = 1e10;
// capacities[offset + 1] = 1e10;
// }
//
// (*added_cuts_count)++;
// if (*added_cuts_count > 10) goto CLEANUP;
// }
// }
//
// // Constraints (2.1)
// for (int i = 0; i < data->cluster_count; i++)
// {
// for (int j = i + 1; j < data->cluster_count; j++)
// {
// struct Node *from = &digraph.nodes[node_count + i];
// struct Node *to = &digraph.nodes[node_count + j];
//
// log_verbose("Calculating max flow from cluster %d to cluster %to\n",
// i, j);
// double flow_value;
// rval = flow_find_max_flow(&digraph, capacities, from, to, flow,
// &flow_value);
// abort_if(rval, "flow_find_max_flow failed");
//
// log_verbose(" %.2lf\n", flow_value);
//
// if (flow_value >= 2 - LP_EPSILON) continue;
//
// log_verbose("violation: %.2lf >= 2\n", flow_value);
//
// int cut_edges_count;
// rval = get_cut_edges_from_marks(&digraph, &cut_edges_count,
// cut_edges);
// abort_if(rval, "get_cut_edges_from_marks failed");
//
// log_verbose("Adding cut for i=%d j=%d, cut edges:\n", i, j);
// int c = 0;
// for (int k = 0; k < cut_edges_count / 2; k++)
// {
// int idx = cut_edges[k * 2]->index / 4;
// if (idx > graph->edge_count) continue;
//
// cut_edges[c++] = &graph->edges[idx];
// log_verbose(" %d %d\n", cut_edges[c - 1]->from->index,
// cut_edges[c - 1]->to->index);
// }
//
// rval = GTSP_add_subtour_elimination_cut_3(lp, graph, from, to,
// cut_edges, c);
// abort_if(rval, "GTSP_add_subtour_elimination_cut3 failed");
//
// (*added_cuts_count)++;
// if (*added_cuts_count > 10) goto CLEANUP;
// }
// }
//
// // subcluster
// struct Node *root = &digraph.nodes[digraph.node_count - 1];
// for (int e_index = 0; e_index < graph->edge_count; e_index++)
// {
// struct Edge *e = &graph->edges[e_index];
// double x_e = x[node_count + e_index];
// if (x_e < LP_EPSILON) continue;
//
// struct Node *from = &digraph.nodes[e->from->index];
// struct Node *to = &digraph.nodes[e->to->index];
//
// if (x[from->index] > 1 - LP_EPSILON && x[to->index] > 1 - LP_EPSILON)
// continue;
//
// capacities[4 * e_index] = capacities[4 * e_index + 2] = 0;
//
// int cluster_from_index = data->clusters[from->index];
// int cluster_to_index = data->clusters[to->index];
//
// for (int k = 0; k < data->cluster_count; k++)
// {
// if (cluster_from_index == k) continue;
// if (cluster_to_index == k) continue;
//
// int offset = 4 * graph->edge_count + 2 * node_count + 2 * k;
// capacities[offset] = 1e10;
// capacities[offset + 1] = 1e10;
// }
//
// for (int k = 0; k < graph->node_count; k++)
// {
// struct Node *n = &graph->nodes[k];
// if (clusters[n->index] != cluster_from_index &&
// clusters[n->index] != cluster_to_index)
// continue;
//
// int offset = 4 * graph->edge_count + 2 * k;
// capacities[offset] = 0;
// capacities[offset + 1] = 0;
// }
//
// // First direction
// log_debug("Calculating max flow from (%d,%d) to root\n", from->index,
// to->index);
// double flow_value;
// rval = flow_find_max_flow(&digraph, capacities, from, root, flow,
// &flow_value);
// abort_if(rval, "flow_find_max_flow failed");
//
// log_debug(" %.2lf\n", flow_value);
//
// if (flow_value + LP_EPSILON < x_e)
// {
// log_debug("violation: %.2lf > %.2lf\n", flow_value, x_e);
//
// int cut_edges_count;
// rval = get_cut_edges_from_marks(&digraph, &cut_edges_count,
// cut_edges);
// abort_if(rval, "get_cut_edges_from_marks failed");
//
// log_debug("Adding cut for i=%d j=root, cut edges:\n", from->index);
// int c = 0;
// for (int k = 0; k < cut_edges_count / 2; k++)
// {
// int idx = cut_edges[k * 2]->index / 4;
// if (idx == e_index) continue;
// if (idx >= graph->edge_count) continue;
//
// cut_edges[c++] = &graph->edges[idx];
// log_debug(" %d %d\n", cut_edges[c - 1]->from->index,
// cut_edges[c - 1]->to->index);
// }
//
// rval = GTSP_add_subcluster_cut(lp, graph, e, cut_edges, c);
// abort_if(rval, "GTSP_add_subcluster_cut failed");
//
// (*added_cuts_count)++;
// if (*added_cuts_count > 10) goto CLEANUP;
//
// } else
// {
// // Reverse direction
// log_debug("Trying reverse edge:\n", to->index, from->index);
//
// rval = flow_find_max_flow(&digraph, capacities, to, root, flow,
// &flow_value);
// abort_if(rval, "flow_find_max_flow failed");
//
// log_debug(" %.2lf\n", flow_value);
//
// if (flow_value + LP_EPSILON < x_e)
// {
// log_debug("violation: %.2lf > %.2lf\n", flow_value, x_e);
//
// int cut_edges_count;
// rval = get_cut_edges_from_marks(&digraph, &cut_edges_count,
// cut_edges);
// abort_if(rval, "get_cut_edges_from_marks failed");
//
// log_debug("Adding cut for i=%d j=root, cut edges:\n",
// from->index);
// int c = 0;
// for (int k = 0; k < cut_edges_count / 2; k++)
// {
// int idx = cut_edges[k * 2]->index / 4;
// if (idx == e_index) continue;
// if (idx >= graph->edge_count) continue;
//
// cut_edges[c++] = &graph->edges[idx];
// log_debug(" %d %d\n", cut_edges[c - 1]->from->index,
// cut_edges[c - 1]->to->index);
// }
//
// rval = GTSP_add_subcluster_cut(lp, graph, e, cut_edges, c);
// abort_if(rval, "GTSP_add_subcluster_cut failed");
//
// (*added_cuts_count)++;
// if (*added_cuts_count > 10) goto CLEANUP;
// }
// }
//
// capacities[4 * e_index] = x_e;
// capacities[4 * e_index + 2] = x_e;
//
// for (int k = 0; k < graph->node_count; k++)
// {
// int offset = 4 * graph->edge_count + 2 * k;
// capacities[offset] = 1e10;
// capacities[offset + 1] = 1e10;
// }
//
// for (int k = 0; k < data->cluster_count; k++)
// {
// int offset = 4 * graph->edge_count + 2 * graph->node_count;
// capacities[offset + 2 * k] = 0;
// capacities[offset + 2 * k + 1] = 0;
// }
// }
CLEANUP:
graph_free(&digraph);
if (flow) free(flow);
if (cut_edges) free(cut_edges);
if (capacities) free(capacities);
if (x) free(x);
return rval;