+
+int is_connected(pbqp_node *node, pbqp_edge *edge)
+{
+ pbqp_edge **edges;
+ unsigned edge_index;
+ unsigned edge_len;
+
+ assert(node);
+ assert(edge);
+
+ if (edge->src != node && edge->tgt != node) return 0;
+
+ edges = node->edges;
+ edge_len = ARR_LEN(edges);
+
+ for (edge_index = 0; edge_index < edge_len; ++edge_index) {
+ pbqp_edge *edge_candidate = edges[edge_index];
+ if (edge_candidate == edge) {
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+void disconnect_edge(pbqp_node *node, pbqp_edge *edge)
+{
+ pbqp_edge **edges;
+ unsigned edge_index;
+ unsigned edge_len;
+
+ edges = node->edges;
+ edge_len = ARR_LEN(edges);
+
+ for (edge_index = 0; edge_index < edge_len; ++edge_index) {
+ pbqp_edge *edge_candidate = edges[edge_index];
+ if (edge_candidate == edge) {
+ edges[edge_index] = edges[edge_len - 1];
+ ARR_SHRINKLEN(edges, (int)edge_len - 1);
+ break;
+ }
+ }
+}
+
+unsigned pbqp_node_get_degree(pbqp_node *node)
+{
+ assert(node);
+ return ARR_LEN(node->edges);
+}
+
+pbqp_node *pbqp_node_deep_copy(pbqp *pbqp, pbqp_node_bucket new_bucket, pbqp_node *node)
+{
+ unsigned edge_index;
+ unsigned edge_length = pbqp_node_get_degree(node);
+ pbqp_node *copy = obstack_alloc(&pbqp->obstack, sizeof(*node));
+ assert(copy);
+
+ copy->edges = NEW_ARR_F(pbqp_edge *, 0);
+ for (edge_index = 0; edge_index < edge_length; ++edge_index) {
+ pbqp_edge *edge_copy;
+ pbqp_edge *edge = node->edges[edge_index];
+ int is_src = edge->src == node;
+
+ if (is_src) {
+ unsigned other_index = edge->tgt->bucket_index;
+ unsigned is_copied = other_index < node->bucket_index;
+
+ if (is_copied) {
+ pbqp_node *other_copy = new_bucket[other_index];
+ unsigned degree = pbqp_node_get_degree(other_copy);
+ unsigned index;
+
+ for (index = 0; index < degree; ++index) {
+ if (other_copy->edges[index]->src == node) {
+ edge_copy = other_copy->edges[index];
+ edge_copy->src = copy;
+ break;
+ }
+ }
+ } else {
+ edge_copy = pbqp_edge_deep_copy(pbqp, edge, copy, edge->tgt);
+ }
+ } else {
+ unsigned other_index = edge->src->bucket_index;
+ unsigned is_copied = other_index < node->bucket_index;
+
+ if (is_copied) {
+ pbqp_node *other_copy = new_bucket[other_index];
+ unsigned degree = pbqp_node_get_degree(other_copy);
+ unsigned index;
+
+ for (index = 0; index < degree; ++index) {
+ if (other_copy->edges[index]->tgt == node) {
+ edge_copy = other_copy->edges[index];
+ edge_copy->tgt = copy;
+ break;
+ }
+ }
+ } else {
+ edge_copy = pbqp_edge_deep_copy(pbqp, edge, edge->src, copy);
+ }
+ }
+ ARR_APP1(pbqp_edge *, copy->edges, edge_copy);
+ }
+ copy->costs = vector_copy(pbqp, node->costs);
+ copy->bucket_index = node->bucket_index;
+ copy->solution = node->solution;
+ copy->index = node->index;
+
+ return copy;
+}