From f2e7b93b02b56792b8a95963e2f804354591f540 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Uhl=C3=ADk?= <jan@uhlik.me>
Date: Thu, 29 Mar 2018 20:55:53 +0200
Subject: [PATCH] Add DFS algorithm.
---
alib2graph_algo/src/traverse/DFS.cpp | 122 ++++++++++++++++
alib2graph_algo/src/traverse/DFS.hpp | 204 +++++++++++++++++++++++++++
2 files changed, 326 insertions(+)
create mode 100644 alib2graph_algo/src/traverse/DFS.cpp
create mode 100644 alib2graph_algo/src/traverse/DFS.hpp
diff --git a/alib2graph_algo/src/traverse/DFS.cpp b/alib2graph_algo/src/traverse/DFS.cpp
new file mode 100644
index 0000000000..d7055514cc
--- /dev/null
+++ b/alib2graph_algo/src/traverse/DFS.cpp
@@ -0,0 +1,122 @@
+// DFS.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 "DFS.hpp"
+
+#include <registration/AlgoRegistration.hpp>
+#include <graph/GraphClasses.hpp>
+#include <grid/GridClasses.hpp>
+
+namespace {
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Normal Graph
+
+auto DFS1 = registration::AbstractRegister<traverse::DFS,
+ ext::vector<DefaultNodeType>,
+ const graph::UndirectedGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::DFS::findPathRegistration);
+
+auto DFS2 = registration::AbstractRegister<traverse::DFS,
+ ext::vector<DefaultNodeType>,
+ const graph::UndirectedMultiGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::DFS::findPathRegistration);
+
+auto DFS3 = registration::AbstractRegister<traverse::DFS,
+ ext::vector<DefaultNodeType>,
+ const graph::DirectedGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::DFS::findPathRegistration);
+
+auto DFS4 = registration::AbstractRegister<traverse::DFS,
+ ext::vector<DefaultNodeType>,
+ const graph::DirectedMultiGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::DFS::findPathRegistration);
+
+auto DFS5 = registration::AbstractRegister<traverse::DFS,
+ ext::vector<DefaultNodeType>,
+ const graph::MixedGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::DFS::findPathRegistration);
+
+auto DFS6 = registration::AbstractRegister<traverse::DFS,
+ ext::vector<DefaultNodeType>,
+ const graph::MixedMultiGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::DFS::findPathRegistration);
+
+auto DFSGrid1 = registration::AbstractRegister<traverse::DFS,
+ ext::vector<DefaultSquareGridNodeType>,
+ const grid::SquareGrid4<> &,
+ const DefaultSquareGridNodeType &,
+ const DefaultSquareGridNodeType &>(traverse::DFS::findPathRegistration);
+
+auto DFSGrid2 = registration::AbstractRegister<traverse::DFS,
+ ext::vector<DefaultSquareGridNodeType>,
+ const grid::SquareGrid8<> &,
+ const DefaultSquareGridNodeType &,
+ const DefaultSquareGridNodeType &>(traverse::DFS::findPathRegistration);
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Weighted Graph
+
+auto WDFS1 = registration::AbstractRegister<traverse::DFS,
+ ext::vector<DefaultNodeType>,
+ const graph::WeightedUndirectedGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::DFS::findPathRegistration);
+
+auto WDFS2 = registration::AbstractRegister<traverse::DFS,
+ ext::vector<DefaultNodeType>,
+ const graph::WeightedUndirectedMultiGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::DFS::findPathRegistration);
+
+auto WDFS3 = registration::AbstractRegister<traverse::DFS,
+ ext::vector<DefaultNodeType>,
+ const graph::WeightedDirectedGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::DFS::findPathRegistration);
+
+auto WDFS4 = registration::AbstractRegister<traverse::DFS,
+ ext::vector<DefaultNodeType>,
+ const graph::WeightedDirectedMultiGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::DFS::findPathRegistration);
+
+auto WDFS5 = registration::AbstractRegister<traverse::DFS,
+ ext::vector<DefaultNodeType>,
+ const graph::WeightedMixedGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::DFS::findPathRegistration);
+
+auto WDFS6 = registration::AbstractRegister<traverse::DFS,
+ ext::vector<DefaultNodeType>,
+ const graph::WeightedMixedMultiGraph<> &,
+ const DefaultNodeType &,
+ const DefaultNodeType &>(traverse::DFS::findPathRegistration);
+
+auto WDFSGrid1 = registration::AbstractRegister<traverse::DFS,
+ ext::vector<DefaultSquareGridNodeType>,
+ const grid::WeightedSquareGrid4<> &,
+ const DefaultSquareGridNodeType &,
+ const DefaultSquareGridNodeType &>(traverse::DFS::findPathRegistration);
+
+auto WDFSGrid2 = registration::AbstractRegister<traverse::DFS,
+ ext::vector<DefaultSquareGridNodeType>,
+ const grid::WeightedSquareGrid8<> &,
+ const DefaultSquareGridNodeType &,
+ const DefaultSquareGridNodeType &>(traverse::DFS::findPathRegistration);
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+}
diff --git a/alib2graph_algo/src/traverse/DFS.hpp b/alib2graph_algo/src/traverse/DFS.hpp
new file mode 100644
index 0000000000..db95256e2e
--- /dev/null
+++ b/alib2graph_algo/src/traverse/DFS.hpp
@@ -0,0 +1,204 @@
+// DFS.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_DFS_HPP
+#define ALIB2_DFS_HPP
+
+#include <functional>
+#include <alib/vector>
+#include <queue>
+#include <alib/set>
+#include <alib/map>
+
+#include <common/ReconstructPath.hpp>
+
+namespace traverse {
+
+class DFS {
+// ---------------------------------------------------------------------------------------------------------------------
+
+ public:
+
+ /// Run DFS algorithm from the \p start node in the \p graph.
+ ///
+ /// 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 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,
+ F f_user = [](const TNode &, const size_t &) -> bool { return false; });
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+ /// Find path using DFS algorithm from the \p start node to the \p goal node in the \p graph.
+ /// However, it is not quarantee that the return path gonna be the shortest one.
+ ///
+ /// 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 f_user function which is called for every opened node with value of currently shortest path.
+ ///
+ /// \returns nodes in 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,
+ 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);
+
+ }
+
+// =====================================================================================================================
+
+ private:
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+ template<typename TNode>
+ struct Data {
+ ext::map<TNode, size_t> d; // distance
+ ext::set<TNode> v; // visited
+ ext::map<TNode, TNode> p; // parents
+ };
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+ template<typename TGraph, typename TNode, typename F1, typename F2>
+ static
+ ext::vector<TNode>
+ impl(const TGraph &graph,
+ const TNode &start,
+ const TNode &goal,
+ F1 f_user,
+ F2 f_stop);
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+ template<typename TGraph, typename TNode, typename F1, typename F2>
+ static
+ bool
+ expansion(const TGraph &graph,
+ DFS::Data<TNode> &data,
+ const TNode &n,
+ const TNode &p,
+ F1 f_user,
+ F2 f_stop);
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+};
+
+// =====================================================================================================================
+
+template<typename TGraph, typename TNode, typename F>
+void DFS::run(const TGraph &graph, const TNode &start, F f_user) {
+ impl(graph, start, start, f_user, [](const TNode &) -> bool { return false; });
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+template<typename TGraph, typename TNode, typename F>
+ext::vector<TNode> DFS::findPath(const TGraph &graph, const TNode &start, const TNode &goal, F f_user) {
+ return impl(graph, start, goal,
+ [&](const TNode &n, const auto &d) -> bool {
+ f_user(n, d);
+ return false;
+ },
+ [&](const TNode &n) -> bool { return goal == n; });
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+template<typename TGraph, typename TNode, typename F1, typename F2>
+ext::vector<TNode> DFS::impl(const TGraph &graph,
+ const TNode &start,
+ const TNode &goal,
+ F1 f_user,
+ F2 f_stop) {
+ Data<TNode> data;
+
+ // Init search
+ data.d[start] = -1;
+
+ // Start DFS
+ expansion(graph, data, start, start, f_user, f_stop);
+
+ return common::ReconstructPath::reconstructPath(data.p, start, goal);
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+template<typename TGraph, typename TNode, typename F1, typename F2>
+bool
+DFS::expansion(const TGraph &graph,
+ DFS::Data<TNode> &data,
+ const TNode &n,
+ const TNode &p,
+ F1 f_user,
+ F2 f_stop) {
+ if (data.v.find(n) != data.v.end()) return false;
+
+ data.v.insert(n);
+ data.p.insert_or_assign(n, p);
+ data.d[n] = data.d[p] + 1;
+
+ // Run user's function
+ if (f_user(n, data.d[n])) {
+ return true; // Stop algorithm
+ }
+
+ // Stop if reach the goal
+ if (f_stop(n)) {
+ return true; // Stop algorithm
+ }
+
+ for (const auto &i : graph.successors(n)) {
+ bool stop = expansion(graph, data, i, n, f_user, f_stop);
+
+ if (stop) {
+ return true;
+ }
+ }
+
+ return false;
+}
+
+
+// =====================================================================================================================
+
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+} // namespace traverse
+#endif //ALIB2_DFS_HPP
--
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