Optimize edmonds karp

bnb/edmonds_karp.cpp

@@ -36,7 +36,7 @@ void edmonds_karp::reset(std::vector<node_id>& sources, std::vector<node_id>& si
 std::pair<int, node_id> edmonds_karp::bfs(std::vector<unsigned int> &pred) const {
 
 	pred.clear();
-	pred.resize(g_.num_nodes() + 1, -1); // undiscovered nodes are marked with -1
+	pred.assign(g_.num_nodes() + 1, -1); // undiscovered nodes are marked with -1
 	std::vector<int> gain(g_.num_nodes() + 1, 0);
 	bool sink_reached = false;
 	node_id sink;
@@ -57,16 +57,12 @@ std::pair<int, node_id> edmonds_karp::bfs(std::vector<unsigned int> &pred) const
 		node_id u = q.front();
 		q.pop();
 
-		const std::vector<node_id> & neighbors = g_.get_adjacency(u);
-
+		const auto& adjacency = g_.get_adjacency(u);
+		const auto& edge_ids = g_.get_edge_ids(u);
 		// iterate through neighbors of u
-		for (node_id v : neighbors) {
-
-			unsigned int edge_id;
-			if ( u < v )
-				edge_id = g_.get_edge_id(u, v);
-			else 
-				edge_id = g_.get_edge_id(v, u);
+		for (node_id i = 0; i < adjacency.size(); ++i) {
+			node_id v  = adjacency[i];
+			edge_id edge_id = edge_ids[i];
 
 			int edge_weight = 1; // unweighted graph