Method decreaseKey

lib/node_ordering/reductions.cpp:163–171

        }

        void decreaseKey(NodeID node, Count decrease) {
                remove_from_bucket(locations[node].first, locations[node].second);
                locations[node].first -= decrease;
                locations[node].second = buckets[locations[node].first].size();
                buckets[locations[node].first].push_back(node);
                if (locations[node].first < (int)min_ptr) {
                        min_ptr = locations[node].first;
                }
        }

        NodeID deleteMin() {
                auto min_node = buckets[min_ptr].back();