diff --git a/alib2graph_algo/src/traverse/IDDFS.cpp b/alib2graph_algo/src/traverse/IDDFS.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..d827cc485f0485f95936237adf4842608104c759
--- /dev/null
+++ b/alib2graph_algo/src/traverse/IDDFS.cpp
@@ -0,0 +1,228 @@
+// IDDFS.cpp
+//
+// Created on: 27. 02. 2018
+// Author: Jan Uhlik
+// Modified by:
+//
+// Copyright (c) 2017 Czech Technical University in Prague | Faculty of Information Technology. All rights reserved.
+// Git repository: https://gitlab.fit.cvut.cz/algorithms-library-toolkit/automata-library
+
+#include "IDDFS.hpp"
+
+#include <registration/AlgoRegistration.hpp>
+#include <graph/GraphClasses.hpp>
+#include <grid/GridClasses.hpp>
+
+namespace traverse {
+class IDDFSBidirectional {};
+}
+
+namespace {
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Normal Graph uni-directional
+
+auto IDDFS1 = registration::AbstractRegister<traverse::IDDFS,
+ ext::vector<DefaultNodeType>,
+ const graph::UndirectedGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathRegistration);
+
+auto IDDFS2 = registration::AbstractRegister<traverse::IDDFS,
+ ext::vector<DefaultNodeType>,
+ const graph::UndirectedMultiGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathRegistration);
+
+auto IDDFS3 = registration::AbstractRegister<traverse::IDDFS,
+ ext::vector<DefaultNodeType>,
+ const graph::DirectedGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathRegistration);
+
+auto IDDFS4 = registration::AbstractRegister<traverse::IDDFS,
+ ext::vector<DefaultNodeType>,
+ const graph::DirectedMultiGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathRegistration);
+
+auto IDDFS5 = registration::AbstractRegister<traverse::IDDFS,
+ ext::vector<DefaultNodeType>,
+ const graph::MixedGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathRegistration);
+
+auto IDDFS6 = registration::AbstractRegister<traverse::IDDFS,
+ ext::vector<DefaultNodeType>,
+ const graph::MixedMultiGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathRegistration);
+
+auto IDDFSGrid1 = registration::AbstractRegister<traverse::IDDFS,
+ ext::vector<DefaultSquareGridNodeType>,
+ const grid::SquareGrid4<> &,
+ const DefaultSquareGridNodeType &,
+ const DefaultSquareGridNodeType &>(traverse::IDDFS::findPathRegistration);
+
+auto IDDFSGrid2 = registration::AbstractRegister<traverse::IDDFS,
+ ext::vector<DefaultSquareGridNodeType>,
+ const grid::SquareGrid8<> &,
+ const DefaultSquareGridNodeType &,
+ const DefaultSquareGridNodeType &>(traverse::IDDFS::findPathRegistration);
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Normal Graph bidirectional
+
+auto IDDFSBidirectional1 = registration::AbstractRegister<traverse::IDDFSBidirectional,
+ ext::vector<DefaultNodeType>,
+ const graph::UndirectedGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathBidirectionalRegistration);
+
+auto IDDFSBidirectional2 = registration::AbstractRegister<traverse::IDDFSBidirectional,
+ ext::vector<DefaultNodeType>,
+ const graph::UndirectedMultiGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathBidirectionalRegistration);
+
+auto IDDFSBidirectional3 = registration::AbstractRegister<traverse::IDDFSBidirectional,
+ ext::vector<DefaultNodeType>,
+ const graph::DirectedGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathBidirectionalRegistration);
+
+auto IDDFSBidirectional4 = registration::AbstractRegister<traverse::IDDFSBidirectional,
+ ext::vector<DefaultNodeType>,
+ const graph::DirectedMultiGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathBidirectionalRegistration);
+
+auto IDDFSBidirectional5 = registration::AbstractRegister<traverse::IDDFSBidirectional,
+ ext::vector<DefaultNodeType>,
+ const graph::MixedGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathBidirectionalRegistration);
+
+auto IDDFSBidirectional6 = registration::AbstractRegister<traverse::IDDFSBidirectional,
+ ext::vector<DefaultNodeType>,
+ const graph::MixedMultiGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathBidirectionalRegistration);
+
+auto IDDFSGridBidirectional1 = registration::AbstractRegister<traverse::IDDFSBidirectional,
+ ext::vector<DefaultSquareGridNodeType>,
+ const grid::SquareGrid4<> &,
+ const DefaultSquareGridNodeType &,
+ const DefaultSquareGridNodeType &>(traverse::IDDFS::findPathBidirectionalRegistration);
+
+auto IDDFSGridbidirectional2 = registration::AbstractRegister<traverse::IDDFSBidirectional,
+ ext::vector<DefaultSquareGridNodeType>,
+ const grid::SquareGrid8<> &,
+ const DefaultSquareGridNodeType &,
+ const DefaultSquareGridNodeType &>(traverse::IDDFS::findPathBidirectionalRegistration);
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Weighted Graph uni-directional
+
+auto WIDDFS1 = registration::AbstractRegister<traverse::IDDFS,
+ ext::vector<DefaultNodeType>,
+ const graph::WeightedUndirectedGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathRegistration);
+
+auto WIDDFS2 = registration::AbstractRegister<traverse::IDDFS,
+ ext::vector<DefaultNodeType>,
+ const graph::WeightedUndirectedMultiGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathRegistration);
+
+auto WIDDFS3 = registration::AbstractRegister<traverse::IDDFS,
+ ext::vector<DefaultNodeType>,
+ const graph::WeightedDirectedGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathRegistration);
+
+auto WIDDFS4 = registration::AbstractRegister<traverse::IDDFS,
+ ext::vector<DefaultNodeType>,
+ const graph::WeightedDirectedMultiGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathRegistration);
+
+auto WIDDFS5 = registration::AbstractRegister<traverse::IDDFS,
+ ext::vector<DefaultNodeType>,
+ const graph::WeightedMixedGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathRegistration);
+
+auto WIDDFS6 = registration::AbstractRegister<traverse::IDDFS,
+ ext::vector<DefaultNodeType>,
+ const graph::WeightedMixedMultiGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathRegistration);
+
+auto WIDDFSGrid1 = registration::AbstractRegister<traverse::IDDFS,
+ ext::vector<DefaultSquareGridNodeType>,
+ const grid::WeightedSquareGrid4<> &,
+ const DefaultSquareGridNodeType &,
+ const DefaultSquareGridNodeType &>(traverse::IDDFS::findPathRegistration);
+
+auto WIDDFSGrid2 = registration::AbstractRegister<traverse::IDDFS,
+ ext::vector<DefaultSquareGridNodeType>,
+ const grid::WeightedSquareGrid8<> &,
+ const DefaultSquareGridNodeType &,
+ const DefaultSquareGridNodeType &>(traverse::IDDFS::findPathRegistration);
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Weighted Graph bidirectional
+
+auto WIDDFSBidirectional1 = registration::AbstractRegister<traverse::IDDFSBidirectional,
+ ext::vector<DefaultNodeType>,
+ const graph::WeightedUndirectedGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathBidirectionalRegistration);
+
+auto WIDDFSBidirectional2 = registration::AbstractRegister<traverse::IDDFSBidirectional,
+ ext::vector<DefaultNodeType>,
+ const graph::WeightedUndirectedMultiGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathBidirectionalRegistration);
+
+auto WIDDFSBidirectional3 = registration::AbstractRegister<traverse::IDDFSBidirectional,
+ ext::vector<DefaultNodeType>,
+ const graph::WeightedDirectedGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathBidirectionalRegistration);
+
+auto WIDDFSBidirectional4 = registration::AbstractRegister<traverse::IDDFSBidirectional,
+ ext::vector<DefaultNodeType>,
+ const graph::WeightedDirectedMultiGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathBidirectionalRegistration);
+
+auto WIDDFSBidirectional5 = registration::AbstractRegister<traverse::IDDFSBidirectional,
+ ext::vector<DefaultNodeType>,
+ const graph::WeightedMixedGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathBidirectionalRegistration);
+
+auto WIDDFSBidirectional6 = registration::AbstractRegister<traverse::IDDFSBidirectional,
+ ext::vector<DefaultNodeType>,
+ const graph::WeightedMixedMultiGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::IDDFS::findPathBidirectionalRegistration);
+
+auto WIDDFSGridBidirectional1 = registration::AbstractRegister<traverse::IDDFSBidirectional,
+ ext::vector<DefaultSquareGridNodeType>,
+ const grid::WeightedSquareGrid4<> &,
+ const DefaultSquareGridNodeType &,
+ const DefaultSquareGridNodeType &>(traverse::IDDFS::findPathBidirectionalRegistration);
+
+auto WIDDFSGridbidirectional2 = registration::AbstractRegister<traverse::IDDFSBidirectional,
+ ext::vector<DefaultSquareGridNodeType>,
+ const grid::WeightedSquareGrid8<> &,
+ const DefaultSquareGridNodeType &,
+ const DefaultSquareGridNodeType &>(traverse::IDDFS::findPathBidirectionalRegistration);
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+}
diff --git a/alib2graph_algo/src/traverse/IDDFS.hpp b/alib2graph_algo/src/traverse/IDDFS.hpp
new file mode 100644
index 0000000000000000000000000000000000000000..36b32e8653f48180f6964bdf936da10997ff8c19
--- /dev/null
+++ b/alib2graph_algo/src/traverse/IDDFS.hpp
@@ -0,0 +1,456 @@
+// IDIDDFS.hpp
+//
+// Created on: 27. 02. 2018
+// Author: Jan Uhlik
+// Modified by:
+//
+// Copyright (c) 2017 Czech Technical University in Prague | Faculty of Information Technology. All rights reserved.
+// Git repository: https://gitlab.fit.cvut.cz/algorithms-library-toolkit/automata-library
+
+#ifndef ALIB2_IDIDDFS_HPP
+#define ALIB2_IDIDDFS_HPP
+
+#include <functional>
+#include <alib/vector>
+#include <queue>
+#include <limits>
+#include <alib/set>
+#include <alib/map>
+
+#include <common/ReconstructPath.hpp>
+
+namespace traverse {
+
+class IDDFS {
+// ---------------------------------------------------------------------------------------------------------------------
+
+ public:
+
+ /// Run IDDFS algorithm from the \p start node in the \p graph.
+ /// Be aware that running this algorithm on a non-tree graph gonna be extremely slow.
+ ///
+ /// Whenever node is opened, \p f_user is called with two parameters (the opened node and distance to this node).
+ /// If return of \p f_user is true, then the algorithm is stopped.
+ ///
+ /// \param graph to explore.
+ /// \param start initial node.
+ /// \param max_depth set maximal allowed depth for IDDFS.
+ /// \param f_user function which is called for every opened node with value of currently shortest path.
+ ///
+ template<
+ typename TGraph,
+ typename TNode,
+ typename F = std::function<bool(const TNode &, const size_t &)>>
+ static
+ void
+ run(const TGraph &graph,
+ const TNode &start,
+ unsigned long max_depth = std::numeric_limits<unsigned long>::max(),
+ F f_user = [](const TNode &, const size_t &) -> bool { return false; });
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+ /// Find the shortest path using IDDFS algorithm from the \p start node to the \p goal node in the \p graph.
+ /// Be aware that running this algorithm on a non-tree graph gonna be extremely slow.
+ ///
+ /// Whenever node is opened, \p f_user is called with two parameters (the opened node and distance to this node).
+ ///
+ /// \param graph to explore.
+ /// \param start initial node.
+ /// \param goal final node.
+ /// \param max_depth set maximal allowed depth for IDDFS.
+ /// \param f_user function which is called for every opened node with value of currently shortest path.
+ ///
+ /// \returns nodes in shortest path, if there is no such path vector is empty.
+ ///
+ template<
+ typename TGraph,
+ typename TNode,
+ typename F = std::function<void(const TNode &, const size_t &)>>
+ static
+ ext::vector<TNode>
+ findPath(const TGraph &graph,
+ const TNode &start,
+ const TNode &goal,
+ unsigned long max_depth = std::numeric_limits<unsigned long>::max(),
+ F f_user = [](const TNode &, const size_t &) {});
+
+ template<typename TGraph, typename TNode>
+ static
+ ext::vector<TNode>
+ findPathRegistration(const TGraph &graph,
+ const TNode &start,
+ const TNode &goal) {
+ return findPath(graph, start, goal);
+
+ }
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+ /// Find the shortest path using IDDFS algorithm from the \p start node to the \p goal node in the \p graph.
+ /// This algorithm is run in both direction, from \p start and also from \p goal.
+ /// Be aware that running this algorithm on a non-tree graph gonna be extremely slow.
+ ///
+ /// Whenever node is opened, \p f_user is called with two parameters (the opened node and distance to this node).
+ ///
+ /// \param graph to explore.
+ /// \param start initial node.
+ /// \param goal final node.
+ /// \param max_depth set maximal allowed depth for IDDFS.
+ /// \param f_user function which is called for every opened node with value of currently shortest path.
+ ///
+ /// \returns nodes in shortest path, if there is no such path vector is empty.
+ ///
+ template<
+ typename TGraph,
+ typename TNode,
+ typename F = std::function<void(const TNode &, const size_t &)>>
+ static
+ ext::vector<TNode>
+ findPathBidirectional(const TGraph &graph,
+ const TNode &start,
+ const TNode &goal,
+ unsigned long max_depth = std::numeric_limits<unsigned long>::max(),
+ F f_user = [](const TNode &, const size_t &) {});
+
+ template<typename TGraph, typename TNode>
+ static
+ ext::vector<TNode>
+ findPathBidirectionalRegistration(const TGraph &graph,
+ const TNode &start,
+ const TNode &goal) {
+ return findPath(graph, start, goal);
+
+ }
+
+// =====================================================================================================================
+
+ private:
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+ template<typename TNode>
+ struct Data {
+ ext::vector<TNode> path; // current path
+ ext::set<TNode> path_set; // current path set for quick search
+ ext::set<TNode> v; // visited
+ };
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+ template<typename TGraph, typename TNode, typename F1, typename F2>
+ static
+ ext::vector<TNode>
+ implNormal(const TGraph &graph,
+ const TNode &start,
+ unsigned long max_depth,
+ F1 f_user,
+ F2 f_stop);
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+ template<typename FSucc, typename TNode, typename F1, typename F2>
+ static
+ bool
+ expansion(FSucc successors,
+ IDDFS::Data<TNode> &data,
+ const TNode &n,
+ bool save_nodes,
+ unsigned long max_depth,
+ F1 f_user,
+ F2 f_stop);
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+ template<typename TGraph, typename TNode, typename F1, typename F2>
+ static
+ ext::vector<TNode>
+ implBidirectional(const TGraph &graph,
+ const TNode &start,
+ const TNode &goal,
+ unsigned long max_depth,
+ F1 f_user,
+ F2 f_stop);
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+ template<typename FSucc, typename TNode, typename F1, typename F2>
+ static
+ ext::set<TNode>
+ backward_expansion(FSucc successors,
+ const IDDFS::Data<TNode> &forward_data,
+ IDDFS::Data<TNode> &backward_data,
+ const TNode &node,
+ unsigned long max_depth,
+ F1 f_user,
+ F2 f_stop);
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+ template<typename TGraph, typename TNode>
+ static
+ ext::vector<TNode>
+ constructPath(const TGraph &graph,
+ const TNode &start,
+ const TNode &goal,
+ TNode intersection,
+ unsigned long max_forward_depth,
+ unsigned long max_backward_depth);
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+ template<typename TNode>
+ inline static void init(IDDFS::Data<TNode> &data, const TNode &start);
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+};
+
+// =====================================================================================================================
+
+template<typename TGraph, typename TNode, typename F>
+void IDDFS::run(const TGraph &graph, const TNode &start, unsigned long max_depth, F f_user) {
+ implNormal(graph, start, max_depth, f_user, [](const TNode &) -> bool { return false; });
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+template<typename TGraph, typename TNode, typename F>
+ext::vector<TNode> IDDFS::findPath(const TGraph &graph,
+ const TNode &start,
+ const TNode &goal,
+ unsigned long max_depth,
+ F f_user) {
+ return implNormal(graph, start, max_depth,
+ [&](const TNode &n, const auto &d) -> bool {
+ f_user(n, d);
+ return false;
+ },
+ [&goal](const TNode &n) -> bool { return goal == n; });
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+template<typename TGraph, typename TNode, typename F>
+ext::vector<TNode> IDDFS::findPathBidirectional(const TGraph &graph,
+ const TNode &start,
+ const TNode &goal,
+ unsigned long max_depth,
+ F f_user) {
+ return implBidirectional(graph, start, goal, max_depth,
+ [&](const TNode &n, const auto &d) -> bool {
+ f_user(n, d);
+ return false;
+ },
+ [](const TNode &) -> bool { return false; });
+}
+
+// =====================================================================================================================
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+template<typename TGraph, typename TNode, typename F1, typename F2>
+ext::vector<TNode> IDDFS::implNormal(const TGraph &graph,
+ const TNode &start,
+ unsigned long max_depth,
+ F1 f_user,
+ F2 f_stop) {
+ for (unsigned long i = 1; i < max_depth; ++i) {
+ Data<TNode> data;
+
+ // Init search
+ init(data, start);
+
+ bool stop =
+ expansion([&](const TNode &node) { return graph.successors(node); }, data, start, false, i, f_user, f_stop);
+
+ if (stop) {
+ return data.path;
+ }
+ }
+
+ return ext::vector<TNode>();
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+template<typename FSucc, typename TNode, typename F1, typename F2>
+bool IDDFS::expansion(FSucc successors,
+ IDDFS::Data<TNode> &data,
+ const TNode &n,
+ bool save_nodes,
+ unsigned long max_depth,
+ F1 f_user,
+ F2 f_stop) {
+ if (max_depth == 0) return false; // Continue with search
+ else if (save_nodes && max_depth == 1) {
+ data.v.insert(n); // Remember only the deepest nodes
+ }
+
+ // Run user's function
+ if (f_user(n, data.path.size())) {
+ return true; // Stop algorithm
+ }
+
+ // Stop if reach the goal
+ if (f_stop(n)) {
+ return true; // Stop algorithm
+ }
+
+ for (const auto &s : successors(n)) {
+
+ // Check if node is not in path
+ if (data.path_set.find(s) != data.path_set.end()) {
+ continue;
+ }
+
+ data.path.push_back(s); // Insert current node
+ data.path_set.insert(s);
+ bool stop = expansion(successors, data, s, save_nodes, max_depth - 1, f_user, f_stop);
+
+ if (stop) {
+ return true; // Stop algorithm
+ }
+
+ data.path.pop_back(); // Remove current node
+ data.path_set.erase(data.path_set.find(s));
+ }
+
+ return false; // Continue with search
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+template<typename TGraph, typename TNode, typename F1, typename F2>
+ext::vector<TNode> IDDFS::implBidirectional(const TGraph &graph,
+ const TNode &start,
+ const TNode &goal,
+ unsigned long max_depth,
+ F1 f_user,
+ F2 f_stop) {
+ for (unsigned long i = 1; i < max_depth; ++i) {
+ // -------------------------------
+ // Forward search
+ Data<TNode> forward_data;
+
+ // Init forward search
+ init(forward_data, start);
+
+ expansion([&](const TNode &n) { return graph.successors(n); }, forward_data, start, true, i, f_user, f_stop);
+
+ // -------------------------------
+ // Backward search
+
+ ext::set<TNode> intersection;
+
+ Data<TNode> backward_data;
+
+ // Init backward search
+ init(backward_data, goal);
+
+ intersection = backward_expansion([&](const TNode &node) { return graph.predecessors(node); },
+ forward_data,
+ backward_data,
+ goal,
+ i,
+ f_user,
+ f_stop); // even run
+
+ // If there is a intersection, then we can construct path
+ if (intersection.size() != 0) {
+ return constructPath(graph, start, goal, *intersection.begin(), i, i);
+ }
+
+ // Init backward search
+ init(backward_data, goal);
+
+ intersection = backward_expansion([&](const TNode &node) { return graph.predecessors(node); },
+ forward_data,
+ backward_data,
+ goal,
+ i + 1,
+ f_user,
+ f_stop); // odd run
+
+ // If there is a intersection, then we can reconstruct path
+ if (intersection.size() != 0) {
+ return constructPath(graph, start, goal, *intersection.begin(), i, i + 1);
+ }
+ }
+
+ return ext::vector<TNode>();
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+template<typename FSucc, typename TNode, typename F1, typename F2>
+ext::set<TNode> IDDFS::backward_expansion(FSucc successors,
+ const IDDFS::Data<TNode> &forward_data,
+ IDDFS::Data<TNode> &backward_data,
+ const TNode &node,
+ unsigned long max_depth,
+ F1 f_user,
+ F2 f_stop) {
+ expansion(successors, backward_data, node, true, max_depth, f_user, f_stop);
+
+ // Check for intersection
+ ext::set<TNode> intersection;
+ std::set_intersection(forward_data.v.begin(), forward_data.v.end(),
+ backward_data.v.begin(), backward_data.v.end(),
+ std::inserter(intersection, intersection.begin()));
+
+ return intersection;
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+template<typename TGraph, typename TNode>
+ext::vector<TNode> IDDFS::constructPath(const TGraph &graph,
+ const TNode &start,
+ const TNode &goal,
+ TNode intersection,
+ unsigned long max_forward_depth,
+ unsigned long max_backward_depth) {
+ Data<TNode> forward_data, backward_data;
+ init(forward_data, start);
+ init(backward_data, goal);
+
+ // Re-run forward search
+ expansion([&](const TNode &node) { return graph.successors(node); },
+ forward_data,
+ start,
+ false,
+ max_forward_depth,
+ [](const TNode &, const size_t &) -> bool { return false; },
+ [&](const TNode &n) -> bool { return n == intersection; }
+ );
+
+ // Re-run backward search
+ expansion([&](const TNode &node) { return graph.predecessors(node); },
+ backward_data,
+ goal,
+ false,
+ max_backward_depth,
+ [](const TNode &, const size_t &) -> bool { return false; },
+ [&](const TNode &n) -> bool { return n == intersection; }
+ );
+
+ return common::ReconstructPath::joinPath(forward_data.path, backward_data.path);
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+template<typename TNode>
+void IDDFS::init(IDDFS::Data<TNode> &data, const TNode &start) {
+ // Make sure that data are wiped
+ data.path.clear();
+ data.v.clear();
+
+ data.path.push_back(start);
+ data.path_set.insert(start);
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+} // namespace traverse
+#endif //ALIB2_IDIDDFS_HPP