diff --git a/CMakeLists.txt b/CMakeLists.txt
index db8dc50..703bedc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -3,6 +3,7 @@ cmake_minimum_required(VERSION 3.10)
 project("Formalang")
 
 # set(CMAKE_CXX_FLAGS "-O3")
+# set(CMAKE_CXX_FLAGS "-O0 --coverage -ftest-coverage -fprofile-arcs")
 
 find_package(GTest REQUIRED)
 find_package(Threads REQUIRED)
@@ -15,14 +16,33 @@ include_directories(
 
 set(CMAKE_CXX_STANDARD 17)
 
-set(SOURCE_FILES)
+set(SOURCE_FILES
+  src/regular/RegularTree.cpp
+  src/regular/RegularTreeNode.cpp
+  src/NFA/NFAGraph.cpp
+  src/NFA/NFAGraphVertex.cpp
+  src/converters/RegularToNFA.cpp
+  src/converters/NFAToDFA.cpp
+  src/DFA/DFAGraph.cpp
+  src/DFA/DFAGraphVertex.cpp
+  src/converters/DFAToFDFA.cpp
+  src/converters/DFAToMinDFA.cpp
+  src/converters/DFAToRegular.cpp
+  src/converters/InvertFDFA.cpp
+  )
 
-set(TEST_FILES)
+set(TEST_FILES
+  tests/regular/ParseRegular.cpp
+  tests/NFAToDFA/CheckEquivalence.cpp
+  tests/regularToDFA/RegularToDFA.cpp
+  tests/DFAToRegular/DFAToRegular.cpp
+  tests/invertFDFA/InvertFDFA.cpp
+  tests/DFAToRegular/DFAToRegular2.cpp
+  tests/DFAToMinDFA/CountSizesMinDFA.cpp
+  )
 
 add_executable(Formalang src/main.cpp ${SOURCE_FILES})
 
-add_executable(Tests tests/test_main.cpp ${TEST_FILES} ${SOURCE_FILES})
+add_executable(Tests tests/MainTest.cpp ${TEST_FILES} ${SOURCE_FILES})
 
 target_link_libraries(Tests ${GTEST_LIBRARIES} Threads::Threads)
-target_link_libraries(Formalang Threads::Threads)
-
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..c18d217
--- /dev/null
+++ b/README.md
@@ -0,0 +1,41 @@
+# Formalang
+```c++
+#include "regular/RegularTree.hpp"
+#include "NFA/NFAGraph.hpp"
+#include "DFA/DFAGraph.hpp"
+#include "converters/RegularToNFA.hpp"
+#include "converters/NFAToDFA.hpp"
+#include "converters/DFAToFDFA.hpp"
+#include "converters/DFAToMinDFA.hpp"
+#include "converters/DFAToRegular.hpp"
+#include "converters/InvertFDFA.hpp"
+
+using namespace regular;
+using namespace NFA;
+using namespace DFA;
+using namespace converters;
+```
+так можно подключить все что есть в моей программе.
+```c++
+RegularTree r("a*"); // Регулярное выражение
+NFAGraph NFA_tree = RegularToNFAGraph(std::move(r)); // В НКА
+DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree)); // В ДКА
+DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph)); // Минимизация
+DFA_graph.Print(); // Мой вывод
+DFA_graph.CreateDotFile("2.dot"); // Вывод в dot файл
+std::string reg = DFAGraphToRegular(std::move(DFA_graph)); // В регулярку
+```
+Такой вывод в регулярку как показано в прошлом примере сделает много лишних скобок, если мы хотим привести к более нормальному виду, то можно сделать так
+```c++
+RegularTree(reg).ToString() // Получится более красивая регулярка
+```
+Про сами регулярки + * - это плюс и звезда Клини. Их можно писать после слов, или после скобок.
+abacaba* ~ (abacaba)\*. a(b)a\* ~ a(b)(a)\*. Для сложения языков используется |. Символом пустого слова является пробел.
+
+Примеры регулярок
+
+a*
+
+a(b)+a
+
+(a|b)*
diff --git a/include/DFA/DFAGraph.hpp b/include/DFA/DFAGraph.hpp
new file mode 100644
index 0000000..f1cb616
--- /dev/null
+++ b/include/DFA/DFAGraph.hpp
@@ -0,0 +1,71 @@
+#pragma once
+
+#include <map>
+#include <vector>
+#include <set>
+#include <memory>
+
+namespace DFA {
+class DFAGraph {
+ public:
+  class Vertex {
+    public:
+     Vertex(DFAGraph* owner);
+
+     bool IsFinal() const;
+     bool IsStart() const;
+     size_t GetNumber() const;
+
+     const std::map<char, size_t>& GetTransitions() const;
+     const std::map<char, size_t>& GetBackTransitions() const;
+
+     void AddEdge(char, size_t);
+     void RemoveEdge(char);
+     void SetOwner(DFAGraph* owner);
+     void SetFinal(bool status);
+     void SetStart(bool status);
+    private:
+     DFAGraph* owner_;
+     std::map<char, size_t> transitions_;
+     std::map<char, size_t> back_transitions_;
+
+     size_t number_;
+     bool is_final_ = false;
+     bool is_start_ = false;
+
+     friend class DFAGraph;
+  };
+
+  DFAGraph() = default;
+  DFAGraph(const DFAGraph&) = delete;
+  DFAGraph(DFAGraph&&);
+
+  DFAGraph& operator=(const DFAGraph&) = delete;
+  DFAGraph& operator=(DFAGraph&&);
+
+  size_t AddNewVertex();
+  void AddFinalVertex(size_t number);
+  void SetStartVertex(size_t number);
+
+  void RemoveVertex(size_t number);
+  void RemoveFinalVertex(size_t number);
+  void RemoveStartVertex(size_t number);
+
+  Vertex& GetVertex(size_t number);
+  bool NotExistVertex(size_t number);
+
+  size_t GetCountVertexes() const;
+  size_t GetReallyCountVertexes() const;
+  const std::vector<size_t>& GetFinalVertexes() const;
+  size_t GetStartVertex() const;
+
+  void Print() const;
+  bool Accepted(const std::string&) const;
+  void CreateDotFile(const std::string& filename) const;
+ private:
+  size_t count_vertexes_ = 0;
+  std::map<size_t, Vertex> vertexes_;
+  std::vector<size_t> final_vertexes_;
+  size_t start_vertex_ = -1;
+};
+}
diff --git a/include/NFA/NFAGraph.hpp b/include/NFA/NFAGraph.hpp
new file mode 100644
index 0000000..db389af
--- /dev/null
+++ b/include/NFA/NFAGraph.hpp
@@ -0,0 +1,74 @@
+#pragma once
+
+#include <map>
+#include <vector>
+#include <set>
+#include <memory>
+
+namespace NFA {
+class NFAGraph {
+ public:
+  class Vertex {
+    public:
+     Vertex(NFAGraph* owner);
+
+     bool IsFinal() const;
+     bool IsStart() const;
+     size_t GetNumber() const;
+
+     const std::map<char, std::set<size_t>>& GetTransitions() const;
+     const std::map<char, std::set<size_t>>& GetBackTransitions() const;
+
+     void AddEdge(char, size_t);
+     void RemoveEdge(char, size_t);
+     void SetOwner(NFAGraph* owner);
+     void SetFinal(bool status);
+     void SetStart(bool status);
+    private:
+     NFAGraph* owner_;
+     std::map<char, std::set<size_t>> transitions_;
+     std::map<char, std::set<size_t>> back_transitions_;
+
+     size_t number_;
+     bool is_final_ = false;
+     bool is_start_ = false;
+
+     friend class NFAGraph;
+  };
+
+  NFAGraph() = default;
+  NFAGraph(const NFAGraph&) = delete;
+  NFAGraph(NFAGraph&&);
+
+  NFAGraph& operator=(const NFAGraph&) = delete;
+  NFAGraph& operator=(NFAGraph&&);
+
+  size_t AddNewVertex();
+  void AddFinalVertex(size_t number);
+  void AddStartVertex(size_t number);
+
+  void RemoveVertex(size_t number);
+  void RemoveFinalVertex(size_t number);
+  void RemoveStartVertex(size_t number);
+
+  void Composition(NFAGraph&&,
+                   std::vector<size_t> start_vertexes,
+                   std::vector<size_t> final_vertexes);
+
+  Vertex& GetVertex(size_t number);
+  bool NotExistVertex(size_t number);
+
+  size_t GetCountVertexes() const;
+  size_t GetReallyCountVertexes() const;
+  const std::vector<size_t>& GetFinalVertexes() const;
+  const std::vector<size_t>& GetStartVertexes() const;
+
+  void Print() const;
+  void CreateDotFile(const std::string& filename) const;
+ private:
+  size_t count_vertexes_ = 0;
+  std::map<size_t, Vertex> vertexes_;
+  std::vector<size_t> final_vertexes_;
+  std::vector<size_t> start_vertexes_;
+};
+}
diff --git a/include/converters/DFAToFDFA.hpp b/include/converters/DFAToFDFA.hpp
new file mode 100644
index 0000000..915d51c
--- /dev/null
+++ b/include/converters/DFAToFDFA.hpp
@@ -0,0 +1,7 @@
+#pragma once
+#include "DFA/DFAGraph.hpp"
+
+namespace converters {
+using namespace DFA;
+DFAGraph DFAGraphToFDFAGraph(DFAGraph&&, const std::vector<char>& alphabet);
+}
diff --git a/include/converters/DFAToMinDFA.hpp b/include/converters/DFAToMinDFA.hpp
new file mode 100644
index 0000000..9791c83
--- /dev/null
+++ b/include/converters/DFAToMinDFA.hpp
@@ -0,0 +1,7 @@
+#pragma once
+#include "DFA/DFAGraph.hpp"
+
+namespace converters {
+using namespace DFA;
+DFAGraph DFAGraphToMinDFAGraph(DFAGraph&&);
+}
diff --git a/include/converters/DFAToRegular.hpp b/include/converters/DFAToRegular.hpp
new file mode 100644
index 0000000..4c825da
--- /dev/null
+++ b/include/converters/DFAToRegular.hpp
@@ -0,0 +1,8 @@
+#pragma once
+#include "DFA/DFAGraph.hpp"
+#include <string>
+
+namespace converters {
+using namespace DFA;
+std::string DFAGraphToRegular(DFAGraph&&);
+}
diff --git a/include/converters/InvertFDFA.hpp b/include/converters/InvertFDFA.hpp
new file mode 100644
index 0000000..e5dce0e
--- /dev/null
+++ b/include/converters/InvertFDFA.hpp
@@ -0,0 +1,7 @@
+#pragma once
+#include "DFA/DFAGraph.hpp"
+
+namespace converters {
+using namespace DFA;
+DFAGraph InvertFDFAGraph(DFAGraph&&);
+}
diff --git a/include/converters/NFAToDFA.hpp b/include/converters/NFAToDFA.hpp
new file mode 100644
index 0000000..66eb908
--- /dev/null
+++ b/include/converters/NFAToDFA.hpp
@@ -0,0 +1,13 @@
+#pragma once
+#include "NFA/NFAGraph.hpp"
+#include "DFA/DFAGraph.hpp"
+
+namespace converters {
+using namespace NFA;
+using namespace DFA;
+NFAGraph AddAllEpsilonTransitions(NFAGraph&&);
+NFAGraph AddAllPossibleFinalVertexes(NFAGraph&&);
+NFAGraph DeleteEpsilonTransitions(NFAGraph&&);
+NFAGraph DeleteTransitionsByOneLetter(NFAGraph&&);
+DFAGraph NFAGraphToDFAGraph(NFAGraph&&);
+}
diff --git a/include/converters/RegularToNFA.hpp b/include/converters/RegularToNFA.hpp
new file mode 100644
index 0000000..dce3ef0
--- /dev/null
+++ b/include/converters/RegularToNFA.hpp
@@ -0,0 +1,10 @@
+#pragma once
+#include "regular/RegularTree.hpp"
+#include "NFA/NFAGraph.hpp"
+
+namespace converters {
+using namespace NFA;
+using namespace regular;
+
+NFAGraph RegularToNFAGraph(RegularTree&&);
+}
diff --git a/include/regular/RegularTree.hpp b/include/regular/RegularTree.hpp
new file mode 100644
index 0000000..3863b3d
--- /dev/null
+++ b/include/regular/RegularTree.hpp
@@ -0,0 +1,44 @@
+#pragma once
+#include <vector>
+#include <memory>
+#include <string>
+#include <string_view>
+
+namespace regular {
+class RegularTree {
+ public:
+  class Node {
+   public:
+    enum class Type {
+      Addition, Concatenation, Word
+    };
+    enum class Modifier {
+      Plus, Star, None
+    };
+
+    Node();
+    Node(Type);
+
+    void Parse(const std::string&);
+    void Print() const;
+    std::vector<std::unique_ptr<Node>> children;
+    std::string word;
+    Type type;
+    Modifier modifier = Modifier::None;
+    std::string ToString() const;
+   private:
+    void ParseCurrentType(const std::string_view);
+    void Compression();
+    void Compression2();
+    void Print(int nesting_level) const;
+  };
+
+  RegularTree(const std::string&);
+  const Node& GetNode() const;
+  void Print() const;
+  std::string ToString() const;
+
+ private:
+  Node node_;
+};
+}
diff --git a/src/DFA/DFAGraph.cpp b/src/DFA/DFAGraph.cpp
new file mode 100644
index 0000000..011df6e
--- /dev/null
+++ b/src/DFA/DFAGraph.cpp
@@ -0,0 +1,149 @@
+#include "DFA/DFAGraph.hpp"
+#include <algorithm>
+#include <iostream>
+#include <fstream>
+
+namespace DFA {
+DFAGraph::DFAGraph(DFAGraph&& another) {
+  std::swap(count_vertexes_, another.count_vertexes_);
+  std::swap(vertexes_, another.vertexes_);
+  std::swap(final_vertexes_, another.final_vertexes_);
+  // TODO
+  // std::swap(start_vertexes_, another.start_vertexes_);
+
+  for (auto& i: vertexes_)
+    i.second.owner_ = this;
+  for (auto& i: another.vertexes_)
+    i.second.owner_ = &another;
+}
+
+DFAGraph& DFAGraph::operator=(DFAGraph&& another) {
+  std::swap(count_vertexes_, another.count_vertexes_);
+  std::swap(vertexes_, another.vertexes_);
+  std::swap(final_vertexes_, another.final_vertexes_);
+  // TODO
+  // std::swap(start_vertexes_, another.start_vertexes_);
+
+  for (auto& i: vertexes_)
+    i.second.owner_ = this;
+  for (auto& i: another.vertexes_)
+    i.second.owner_ = &another;
+  return *this;
+}
+size_t DFAGraph::AddNewVertex() {
+  vertexes_.emplace(count_vertexes_, this);
+  GetVertex(count_vertexes_).number_ = count_vertexes_;
+  return count_vertexes_++;
+}
+
+void DFAGraph::AddFinalVertex(size_t number) {
+  if (!GetVertex(number).is_final_) {
+    GetVertex(number).is_final_ = true;
+    final_vertexes_.push_back(number);
+  }
+}
+
+void DFAGraph::SetStartVertex(size_t number) {
+  if (!GetVertex(number).is_start_) {
+    GetVertex(number).is_start_ = true;
+    start_vertex_ = number;
+  }
+}
+
+void DFAGraph::RemoveVertex(size_t number) {
+  RemoveFinalVertex(number);
+  RemoveStartVertex(number);
+  vertexes_.erase(number);
+  if (number == count_vertexes_ - 1) count_vertexes_--;
+}
+
+void DFAGraph::RemoveFinalVertex(size_t number) {
+  for (size_t i = 0; i < final_vertexes_.size(); ++i) {
+    if (final_vertexes_[i] == number) {
+      GetVertex(number).is_final_ = false;
+      std::swap(final_vertexes_[i], final_vertexes_.back());
+      final_vertexes_.pop_back();
+      break;
+    }
+  }
+}
+
+void DFAGraph::RemoveStartVertex(size_t number) {
+  if (start_vertex_ == number) {
+    start_vertex_ = -1;
+  }
+}
+
+DFAGraph::Vertex& DFAGraph::GetVertex(size_t number) {
+  if (!NotExistVertex(number))
+    return vertexes_.at(number);
+  throw std::out_of_range("This vertex don't exist");
+}
+
+bool DFAGraph::NotExistVertex(size_t number) {
+  return !vertexes_.count(number);
+}
+
+size_t DFAGraph::GetCountVertexes() const {
+  return count_vertexes_;
+}
+
+size_t DFAGraph::GetReallyCountVertexes() const {
+  return vertexes_.size();
+}
+
+const std::vector<size_t>& DFAGraph::GetFinalVertexes() const {
+  return final_vertexes_;
+}
+
+size_t DFAGraph::GetStartVertex() const {
+  return start_vertex_;
+}
+
+void DFAGraph::Print() const {
+  for (auto i: vertexes_) {
+    std::cout << i.second.number_ << " " << "f-" << i.second.is_final_ << " s-" <<
+        i.second.is_start_ << std::endl;
+  }
+  for (auto& i: vertexes_) {
+    for (auto& j: i.second.transitions_) {
+      std::cout << i.second.number_ << "->" << j.second << " <" << j.first << ">" <<
+          std::endl;
+    }
+  }
+  std::cout << std::endl;
+}
+
+bool DFAGraph::Accepted(const std::string& str) const {
+  size_t current = start_vertex_;
+  for (auto i: str) {
+    if (vertexes_.at(current).GetTransitions().count(i)) {
+      current = vertexes_.at(vertexes_.at(current).GetTransitions().at(i)).GetNumber();
+    } else {
+      return false;
+    }
+  }
+  return vertexes_.at(current).IsFinal();
+}
+
+void DFAGraph::CreateDotFile(const std::string& filename) const {
+  std::ofstream out(filename);
+  out << "digraph G {\n";
+
+  for (auto& i: vertexes_) {
+    for (auto& j: i.second.transitions_) {
+      out << i.first << "->" << j.second << "[label=" << j.first << "]\n";
+    }
+    if (i.second.IsStart() && i.second.IsFinal()) {
+      out << "  " << i.first << " [shape=star];\n";
+    } else if (i.second.IsStart()) {
+      out << "  " << i.first << " [shape=rarrow];\n";
+    } else if (i.second.IsFinal()) {
+      out << "  " << i.first << " [shape=Msquare];\n";
+    }
+  }
+
+  out << "}\n";
+}
+}
+
diff --git a/src/DFA/DFAGraphVertex.cpp b/src/DFA/DFAGraphVertex.cpp
new file mode 100644
index 0000000..ddad254
--- /dev/null
+++ b/src/DFA/DFAGraphVertex.cpp
@@ -0,0 +1,57 @@
+#include "DFA/DFAGraph.hpp"
+
+using Vertex = DFA::DFAGraph::Vertex;
+
+Vertex::Vertex(DFAGraph* owner) : owner_(owner) {}
+
+bool Vertex::IsFinal() const {
+  return is_final_;
+}
+
+bool Vertex::IsStart() const {
+  return is_start_;
+}
+
+size_t Vertex::GetNumber() const {
+  return number_;
+}
+
+const std::map<char, size_t>& Vertex::GetTransitions() const {
+  return transitions_;
+}
+
+const std::map<char, size_t>& Vertex::GetBackTransitions() const {
+  return back_transitions_;
+}
+
+void Vertex::AddEdge(char symbol, size_t number) {
+  transitions_[symbol] = number;
+  owner_->GetVertex(number).back_transitions_[symbol] = number_;
+}
+
+void Vertex::RemoveEdge(char symbol) {
+  owner_->GetVertex(transitions_[symbol]).back_transitions_.erase(symbol);
+  transitions_.erase(symbol);
+}
+
+void Vertex::SetOwner(DFAGraph* owner) {
+  owner_ = owner;
+}
+
+void Vertex::SetFinal(bool status) {
+  if (status != is_final_) {
+    if (status)
+      owner_->AddFinalVertex(number_);
+    else
+      owner_->RemoveFinalVertex(number_);
+  }   
+}
+
+void Vertex::SetStart(bool status) {
+  if (status != is_start_) {
+    if (status)
+      owner_->SetStartVertex(number_);
+    else
+      owner_->RemoveStartVertex(number_);
+  }   
+}
diff --git a/src/NFA/NFAGraph.cpp b/src/NFA/NFAGraph.cpp
new file mode 100644
index 0000000..2d31831
--- /dev/null
+++ b/src/NFA/NFAGraph.cpp
@@ -0,0 +1,202 @@
+#include "NFA/NFAGraph.hpp"
+#include <algorithm>
+#include <iostream>
+#include <fstream>
+
+namespace NFA {
+NFAGraph::NFAGraph(NFAGraph&& another) {
+  std::swap(count_vertexes_, another.count_vertexes_);
+  std::swap(vertexes_, another.vertexes_);
+  std::swap(final_vertexes_, another.final_vertexes_);
+  std::swap(start_vertexes_, another.start_vertexes_);
+
+  for (auto& i: vertexes_)
+    i.second.owner_ = this;
+  for (auto& i: another.vertexes_)
+    i.second.owner_ = &another;
+}
+
+NFAGraph& NFAGraph::operator=(NFAGraph&& another) {
+  std::swap(count_vertexes_, another.count_vertexes_);
+  std::swap(vertexes_, another.vertexes_);
+  std::swap(final_vertexes_, another.final_vertexes_);
+  std::swap(start_vertexes_, another.start_vertexes_);
+
+  for (auto& i: vertexes_)
+    i.second.owner_ = this;
+  for (auto& i: another.vertexes_)
+    i.second.owner_ = &another;
+  return *this;
+}
+
+size_t NFAGraph::AddNewVertex() {
+  vertexes_.emplace(count_vertexes_, this);
+  GetVertex(count_vertexes_).number_ = count_vertexes_;
+  return count_vertexes_++;
+}
+
+void NFAGraph::AddFinalVertex(size_t number) {
+  if (!GetVertex(number).is_final_) {
+    GetVertex(number).is_final_ = true;
+    final_vertexes_.push_back(number);
+  }
+}
+
+void NFAGraph::AddStartVertex(size_t number) {
+  if (!GetVertex(number).is_start_) {
+    GetVertex(number).is_start_ = true;
+    start_vertexes_.push_back(number);
+  }
+}
+
+void NFAGraph::RemoveVertex(size_t number) {
+  RemoveFinalVertex(number);
+  RemoveStartVertex(number);
+  vertexes_.erase(number);
+}
+
+void NFAGraph::RemoveFinalVertex(size_t number) {
+  for (size_t i = 0; i < final_vertexes_.size(); ++i) {
+    if (final_vertexes_[i] == number) {
+      GetVertex(number).is_final_ = false;
+      std::swap(final_vertexes_[i], final_vertexes_.back());
+      final_vertexes_.pop_back();
+      break;
+    }
+  }
+}
+
+void NFAGraph::RemoveStartVertex(size_t number) {
+  for (size_t i = 0; i < start_vertexes_.size(); ++i) {
+    if (start_vertexes_[i] == number) {
+      GetVertex(number).is_start_ = false;
+      std::swap(start_vertexes_[i], start_vertexes_.back());
+      start_vertexes_.pop_back();
+      break;
+    }
+  }
+}
+
+void NFAGraph::Composition(NFAGraph&& nfa_graph,
+                          std::vector<size_t> start_vertexes,
+                          std::vector<size_t> final_vertexes) {
+  auto add_final_vertexes = nfa_graph.final_vertexes_;
+  auto add_start_vertexes = nfa_graph.start_vertexes_;
+
+  size_t new_count_vertexes = count_vertexes_;
+
+  for (auto& i: nfa_graph.vertexes_) {
+    new_count_vertexes = std::max(new_count_vertexes, i.first + count_vertexes_ + 1);
+    i.second.number_ += count_vertexes_;
+    std::map<char, std::set<size_t>> new_transitions;
+    for (auto& j: i.second.transitions_) {
+      for (auto& k: j.second) {
+        new_transitions[j.first].insert(k + count_vertexes_);
+      }
+    }
+    std::map<char, std::set<size_t>> new_back_transitions;
+    for (auto& j: i.second.back_transitions_) {
+      for (auto& k: j.second) {
+        new_back_transitions[j.first].insert(k + count_vertexes_);
+      }
+    }
+    i.second.transitions_ = std::move(new_transitions);
+    i.second.back_transitions_ = std::move(new_back_transitions);
+
+    i.second.SetOwner(this);
+    vertexes_.emplace(i.second.number_, std::move(i.second));
+  }
+
+  for (auto& i: add_start_vertexes) {
+    i += count_vertexes_;
+  }
+  for (auto& i: add_final_vertexes) {
+    i += count_vertexes_;
+  }
+
+  count_vertexes_ = new_count_vertexes;
+
+  for (auto& i: start_vertexes) {
+    for (auto& j: add_start_vertexes) {
+      GetVertex(i).transitions_[' '].insert(j);
+      GetVertex(j).back_transitions_[' '].insert(i);
+    }
+  }
+  for (auto& i: add_final_vertexes) {
+    for (auto& j: final_vertexes) {
+      GetVertex(i).transitions_[' '].insert(j);
+      GetVertex(j).back_transitions_[' '].insert(i);
+    }
+  }
+  for (auto& i: add_final_vertexes) {
+    GetVertex(i).is_final_ = false;
+  }
+  for (auto& i: add_start_vertexes) {
+    GetVertex(i).is_start_ = false;
+  }
+}
+
+NFAGraph::Vertex& NFAGraph::GetVertex(size_t number) {
+  if (!NotExistVertex(number))
+    return vertexes_.at(number);
+  throw std::out_of_range("This vertex don't exist");
+}
+
+bool NFAGraph::NotExistVertex(size_t number) {
+  return !vertexes_.count(number);
+}
+
+size_t NFAGraph::GetCountVertexes() const {
+  return count_vertexes_;
+}
+
+size_t NFAGraph::GetReallyCountVertexes() const {
+  return vertexes_.size();
+}
+
+const std::vector<size_t>& NFAGraph::GetFinalVertexes() const {
+  return final_vertexes_;
+}
+
+const std::vector<size_t>& NFAGraph::GetStartVertexes() const {
+  return start_vertexes_;
+}
+
+void NFAGraph::Print() const {
+  for (auto i: vertexes_) {
+    std::cout << i.second.number_ << " " << "f-" << i.second.is_final_ << " s-" <<
+        i.second.is_start_ << std::endl;
+  }
+  for (auto& i: vertexes_) {
+    for (auto& j: i.second.transitions_) {
+      for (auto k: j.second) {
+        std::cout << i.second.number_ << "." << k << " <" << j.first << ">" <<
+            std::endl;
+      }   
+    }
+  }
+  std::cout << std::endl;
+}
+
+void NFAGraph::CreateDotFile(const std::string& filename) const {
+  std::ofstream out(filename);
+  out << "digraph G {\n";
+
+  for (auto& i: vertexes_) {
+    for (auto& j: i.second.transitions_) {
+      for (auto& k: j.second) {
+        out << i.first << "." << k << "[label=" << j.first << "]\n";
+      }
+    }
+    if (i.second.IsStart() && i.second.IsFinal()) {
+      out << "  " << i.first << " [shape=Mstar];\n";
+    } else if (i.second.IsStart()) {
+      out << "  " << i.first << " [shape=Mdiamond];\n";
+    } else if (i.second.IsFinal()) {
+      out << "  " << i.first << " [shape=Msquare];\n";
+    }
+  }
+
+  out << "}\n";
+}
+}
diff --git a/src/NFA/NFAGraphVertex.cpp b/src/NFA/NFAGraphVertex.cpp
new file mode 100644
index 0000000..32610a9
--- /dev/null
+++ b/src/NFA/NFAGraphVertex.cpp
@@ -0,0 +1,62 @@
+#include "NFA/NFAGraph.hpp"
+
+using Vertex = NFA::NFAGraph::Vertex;
+
+Vertex::Vertex(NFAGraph* owner) : owner_(owner) {}
+
+bool Vertex::IsFinal() const {
+  return is_final_;
+}
+
+bool Vertex::IsStart() const {
+  return is_start_;
+}
+
+size_t Vertex::GetNumber() const {
+  return number_;
+}
+
+const std::map<char, std::set<size_t>>& Vertex::GetTransitions() const {
+  return transitions_;
+}
+
+const std::map<char, std::set<size_t>>& Vertex::GetBackTransitions() const {
+  return back_transitions_;
+}
+
+void Vertex::AddEdge(char symbol, size_t number) {
+  transitions_[symbol].insert(number);
+  owner_->GetVertex(number).back_transitions_[symbol];
+  owner_->GetVertex(number).back_transitions_[symbol].insert(number_);
+}
+
+void Vertex::RemoveEdge(char symbol, size_t number) {
+  transitions_[symbol].erase(number);
+  if (transitions_[symbol].size() == 0)
+    transitions_.erase(symbol);
+  owner_->GetVertex(number).back_transitions_[symbol].erase(number_);
+  if (owner_->GetVertex(number).back_transitions_[symbol].size() == 0)
+    owner_->GetVertex(number).back_transitions_.erase(symbol);
+}
+
+void Vertex::SetOwner(NFAGraph* owner) {
+  owner_ = owner;
+}
+
+void Vertex::SetFinal(bool status) {
+  if (status != is_final_) {
+    if (status)
+      owner_->AddFinalVertex(number_);
+    else
+      owner_->RemoveFinalVertex(number_);
+  }   
+}
+
+void Vertex::SetStart(bool status) {
+  if (status != is_start_) {
+    if (status)
+      owner_->AddStartVertex(number_);
+    else
+      owner_->RemoveStartVertex(number_);
+  }   
+}
diff --git a/src/converters/DFAToFDFA.cpp b/src/converters/DFAToFDFA.cpp
new file mode 100644
index 0000000..6b7245d
--- /dev/null
+++ b/src/converters/DFAToFDFA.cpp
@@ -0,0 +1,46 @@
+#include "converters/DFAToFDFA.hpp"
+
+namespace converters {
+DFAGraph DFAGraphToFDFAGraph(DFAGraph&& graph, const std::vector<char>& alphabet) {
+  DFAGraph result;
+  const int n = graph.GetCountVertexes();
+  std::map<size_t, size_t> number_vertex_in_DFA;
+  for (int i = 0; i < n; ++i) {
+    if (graph.NotExistVertex(i)) continue;
+    number_vertex_in_DFA[i] = result.AddNewVertex();
+  }
+  for (int i = 0; i < n; ++i) {
+    if (graph.NotExistVertex(i)) continue;
+    if (graph.GetVertex(i).IsFinal())
+      result.GetVertex(number_vertex_in_DFA[i]).SetFinal(true);
+    if (graph.GetVertex(i).IsStart())
+      result.GetVertex(number_vertex_in_DFA[i]).SetStart(true);
+
+    const auto& transitions = graph.GetVertex(i).GetTransitions();
+    for (const auto& t: transitions) {
+      result.GetVertex(number_vertex_in_DFA[i]).AddEdge(t.first, t.second);
+    }
+  }
+
+  size_t drain = result.AddNewVertex();
+
+  for (int i = 0; i < n; ++i) {
+    const auto& transitions = graph.GetVertex(i).GetTransitions();
+    for (char j: alphabet) {
+      if (!transitions.count(j)) {
+        result.GetVertex(i).AddEdge(j, drain);
+      }
+    }
+  }
+
+  if (result.GetVertex(drain).GetBackTransitions().size() == 0) {
+    result.RemoveVertex(drain);
+  } else {
+    for (char j: alphabet) {
+      result.GetVertex(drain).AddEdge(j, drain);
+    }
+  }
+
+  return result;
+}
+}
diff --git a/src/converters/DFAToMinDFA.cpp b/src/converters/DFAToMinDFA.cpp
new file mode 100644
index 0000000..af52be9
--- /dev/null
+++ b/src/converters/DFAToMinDFA.cpp
@@ -0,0 +1,111 @@
+#include "converters/DFAToMinDFA.hpp"
+#include <iostream>
+
+namespace converters {
+DFAGraph DFAGraphToMinDFAGraph(DFAGraph&& graph) {
+  const int n = graph.GetCountVertexes();
+  DFAGraph result;
+
+  std::vector<char> alphabet;
+  
+  {
+    std::set<char> set_alphabet;
+    for (int i = 0; i < n; ++i) {
+      if (graph.NotExistVertex(i)) continue;
+      for (auto i: graph.GetVertex(i).GetTransitions()) {
+        set_alphabet.insert(i.first);
+      }
+    }
+    alphabet = std::vector<char>(set_alphabet.begin(), set_alphabet.end());
+  }
+
+  std::vector<std::vector<std::vector<size_t>>> table(n,
+    std::vector<std::vector<size_t>>(n, std::vector<size_t>(alphabet.size() + 1)));
+  
+  {
+    std::vector<std::vector<size_t>>& layer(table[0]);
+    for (int i = 0; i < n; ++i) {
+      layer[i][0] = graph.GetVertex(i).IsFinal();
+    }
+    for (int i = 0; i < n; ++i) {
+      for (int j = 0; j < alphabet.size(); ++j) {
+        const auto& transitions = graph.GetVertex(i).GetTransitions();
+        if (transitions.count(alphabet[j]))
+          layer[i][j + 1] = layer[transitions.at(alphabet[j])][0];
+        else
+          layer[i][j + 1] = -1;
+      }
+    }
+  }
+  
+  for (int number_layer = 1; number_layer < n; ++number_layer) {
+    size_t count_types = 0;
+    std::vector<std::vector<size_t>>& prev_layer(table[number_layer - 1]);
+    std::vector<std::vector<size_t>>& layer(table[number_layer]);
+    for (int i = 0; i < n; ++i) {
+      bool is_find = false;
+      for (int j = 0; j < i; ++j) {
+        if (prev_layer[j] == prev_layer[i]) {
+          layer[i][0] = layer[j][0];
+          is_find = true;
+          break;
+        }
+      } 
+      if (!is_find) {
+        layer[i][0] = count_types++;
+      }
+    }
+    for (int i = 0; i < n; ++i) {
+      for (int j = 0; j < alphabet.size(); ++j) {
+        const auto& transitions = graph.GetVertex(i).GetTransitions();
+        if (transitions.count(alphabet[j]))
+          layer[i][j + 1] = layer[transitions.at(alphabet[j])][0];
+        else
+          layer[i][j + 1] = -1LL;
+      }
+    }
+  }
+
+  /*
+  for (int i = 0; i < n; ++i) {
+    for (int k = 0; k < n; ++k) {
+      for (int j = 0; j < alphabet.size() + 1; ++j) {
+        std::cout << table[k][i][j] << " ";
+      }
+      std::cout << "| ";
+    }
+    std::cout << std::endl;
+  }
+   */
+
+  std::vector<std::vector<size_t>>& last_layer(table.back());
+  size_t count_vertex = 0;
+
+  for (int i = 0; i < n; ++i) {
+    count_vertex = std::max(count_vertex, last_layer[i][0]);
+  }
+  count_vertex++;
+
+  std::map<size_t, size_t> number_vertex_in_DFA;
+  for (int i = 0; i < count_vertex; ++i) {
+    number_vertex_in_DFA[i] = result.AddNewVertex();
+  }
+
+  for (int i = 0; i < n; ++i) {
+    size_t v = number_vertex_in_DFA[last_layer[i][0]];
+
+    const auto& transitions = graph.GetVertex(i).GetTransitions();
+    for (const auto& t: transitions) {
+      if (last_layer[t.second][0] != -1LL) {
+        size_t u = number_vertex_in_DFA[last_layer[t.second][0]];
+        result.GetVertex(v).AddEdge(t.first, u);
+      } 
+    }
+
+    if (graph.GetVertex(i).IsStart()) result.GetVertex(v).SetStart(true);
+    if (graph.GetVertex(i).IsFinal()) result.GetVertex(v).SetFinal(true);
+  }
+
+  return result;
+}
+}
diff --git a/src/converters/DFAToRegular.cpp b/src/converters/DFAToRegular.cpp
new file mode 100644
index 0000000..ffd6f0c
--- /dev/null
+++ b/src/converters/DFAToRegular.cpp
@@ -0,0 +1,124 @@
+#include "converters/DFAToRegular.hpp"
+
+namespace converters {
+std::string DFAGraphToRegular(DFAGraph&& graph) {
+  const size_t n = graph.GetCountVertexes() + 1;
+  std::string result = "";
+
+  std::vector<std::vector<std::set<std::string>>> transitions(n,
+               std::vector<std::set<std::string>>(n));
+
+  std::map<size_t, size_t> rename;
+  size_t start = -1;
+
+  for (int i = 0; i < n - 1; ++i) {
+    if (graph.NotExistVertex(i)) continue;
+    if (graph.GetVertex(i).IsStart()) start = i;
+  }
+
+  rename[start] = 1;
+  int cnt = 2;
+
+  for (int i = 0; i < n - 1; ++i) {
+    if (i == start) continue;
+    rename[i] = cnt++;
+  }
+
+
+  for (int i = 0; i < n - 1; ++i) {
+    if (graph.NotExistVertex(i)) continue;
+    const auto& vertex_transitions = graph.GetVertex(i).GetTransitions();
+
+    for (auto j: vertex_transitions) {
+      transitions[rename[i]][rename[j.second]].insert(std::string(1, j.first));
+    }
+    if (graph.GetVertex(i).IsFinal()) {
+      transitions[rename[i]][0].insert("( )");
+    }
+  }
+
+  for (int i = n - 1; i > 1; --i) {
+    std::vector<std::vector<std::set<std::string>>> new_transitions(n,
+                    std::vector<std::set<std::string>>(n));
+    std::string loop = "";
+    if (transitions[i][i].size() != 0) {
+      for (const std::string s: transitions[i][i]) {
+        loop += "(";
+        loop += s;
+        loop += ")";
+        loop += "|";
+      }
+      if (loop.size())
+        loop.pop_back();
+      if (transitions[i][i].size() > 1)
+        loop = "(" + loop + ")*";
+      else
+        loop += "*";
+    }
+
+    for (int j = 0; j < i; ++j) {
+      if (transitions[j][i].size() == 0) continue;
+      std::string j_to_i = "";
+      for (const std::string s: transitions[j][i]) {
+        j_to_i += "(";
+        j_to_i += s;
+        j_to_i += ")";
+        j_to_i += "|";
+      }
+      if (j_to_i.size())
+        j_to_i.pop_back();
+      if (transitions[j][i].size() > 1)
+        j_to_i = "(" + j_to_i + ")";
+
+      for (int k = 0; k < i; ++k) {
+      if (transitions[i][k].size() == 0) continue;
+        std::string i_to_k = "";
+        for (const std::string s: transitions[i][k]) {
+          i_to_k += "(";
+          i_to_k += s;
+          i_to_k += ")";
+          i_to_k += "|";
+        }
+        if (i_to_k.size())
+          i_to_k.pop_back();
+        if (transitions[i][k].size() > 1)
+          i_to_k = "(" + j_to_i + ")";
+
+        new_transitions[j][k].insert(j_to_i + loop + i_to_k);
+      }
+    }
+
+    for (int j = 0; j < i; ++j) {
+      for (int k = 0; k < i; ++k) {
+        transitions[j][k].insert(new_transitions[j][k].begin(), new_transitions[j][k].end());
+      }
+    }
+  }
+
+  std::string loop;
+  std::string begin_to_end;
+
+  if (transitions[1][1].size() != 0) {
+    for (const std::string& s: transitions[1][1]) {
+      loop += "(";
+      loop += s;
+      loop += ")";
+      loop += "|";
+    }
+    if (loop.size())
+      loop.pop_back();
+    loop = "(" + loop + ")*";
+  }
+  for (const std::string& s: transitions[1][0]) {
+    begin_to_end += "(";
+    begin_to_end += s;
+    begin_to_end += ")";
+    begin_to_end += "|";
+  }
+  if (begin_to_end.size())
+    begin_to_end.pop_back();
+  
+  std::string res(loop + "(" + begin_to_end + ")");
+  return res;
+}
+}
diff --git a/src/converters/InvertFDFA.cpp b/src/converters/InvertFDFA.cpp
new file mode 100644
index 0000000..429060b
--- /dev/null
+++ b/src/converters/InvertFDFA.cpp
@@ -0,0 +1,12 @@
+#include "converters/InvertFDFA.hpp"
+
+namespace converters {
+DFAGraph InvertFDFAGraph(DFAGraph&& fdfa_graph) {
+  const size_t n = fdfa_graph.GetCountVertexes();
+  for (int i = 0; i < n; ++i) {
+    if (fdfa_graph.NotExistVertex(i)) continue;
+    fdfa_graph.GetVertex(i).SetFinal(!fdfa_graph.GetVertex(i).IsFinal());
+  }
+  return std::move(fdfa_graph);
+}
+}
diff --git a/src/converters/NFAToDFA.cpp b/src/converters/NFAToDFA.cpp
new file mode 100644
index 0000000..843fc06
--- /dev/null
+++ b/src/converters/NFAToDFA.cpp
@@ -0,0 +1,183 @@
+#include "converters/NFAToDFA.hpp"
+#include <functional>
+#include <queue>
+#include <stdexcept>
+
+namespace converters {
+NFAGraph AddAllEpsilonTransitions(NFAGraph&& nfa_graph) {
+  const int n = nfa_graph.GetCountVertexes();
+  std::vector<bool> used(n, false);
+
+  std::function<void(int, int)> dfs = [&nfa_graph, &used, &dfs](int u, int v) -> void {
+    used[v] = true;
+    const auto& transitions = nfa_graph.GetVertex(v).GetTransitions();
+    if (transitions.count(' ')) {
+      const auto& s = transitions.at(' ');
+      for (auto i: s) {
+        if (!used[i]) {
+          if (u != i)
+            nfa_graph.GetVertex(u).AddEdge(' ', i);
+          dfs(u, i);
+        }
+      }
+    }
+  };
+
+  for (int i = 0; i < n; ++i) {
+    if (nfa_graph.NotExistVertex(i)) continue;
+
+    used.assign(n, false);
+    dfs(i, i);
+  }
+  return std::move(nfa_graph);
+}
+
+NFAGraph AddAllPossibleFinalVertexes(NFAGraph&& nfa_graph) {
+  if (nfa_graph.GetStartVertexes().size() != 1) {
+    size_t start_vertex = nfa_graph.AddNewVertex();
+    for (auto v: nfa_graph.GetStartVertexes()) {
+      nfa_graph.GetVertex(start_vertex).AddEdge(' ', v);
+    }
+  }
+  for (const auto& v: nfa_graph.GetFinalVertexes()) {
+    const auto& transitions = nfa_graph.GetVertex(v).GetBackTransitions();
+    if (transitions.count(' ')) {
+      const auto& s = transitions.at(' ');
+      for (auto i: s) {
+        nfa_graph.GetVertex(i).SetFinal(true);
+      }
+    } 
+  }
+  return std::move(nfa_graph);
+}
+
+NFAGraph DeleteEpsilonTransitions(NFAGraph&& nfa_graph) {
+  const int n = nfa_graph.GetCountVertexes();
+
+  for (int v = 0; v < n; ++v) {
+    if (nfa_graph.NotExistVertex(v)) continue;
+
+    const auto& transitions = nfa_graph.GetVertex(v).GetTransitions();
+    if (transitions.count(' ')) {
+      auto s = transitions.at(' ');
+      for (auto u: s) {
+        for (auto& i: nfa_graph.GetVertex(u).GetTransitions()) {
+          if (i.first == ' ') continue;
+          for (auto t: i.second) {
+            nfa_graph.GetVertex(v).AddEdge(i.first, t);
+          } 
+        }
+      }
+      for (auto u: s) {
+        nfa_graph.GetVertex(v).RemoveEdge(' ', u);
+      }   
+    }
+  }
+  return std::move(nfa_graph);
+}
+
+NFAGraph DeleteTransitionsByOneLetter(NFAGraph&& nfa_graph) {
+  const int n = nfa_graph.GetCountVertexes();
+
+  NFAGraph result_tree;
+
+  std::map<std::pair<std::set<size_t>, char>, std::set<size_t>> transitions;
+  std::map<std::set<size_t>, size_t> number_vertex_in_result_tree;
+  std::queue<std::set<size_t>> queue;
+
+  std::set<char> alphabet;
+  for (int i = 0; i < n; ++i) {
+    if (nfa_graph.NotExistVertex(i)) continue;
+    for (const auto& j: nfa_graph.GetVertex(i).GetTransitions()) {
+      if (j.second.size() > 0)
+        alphabet.insert(j.first);
+    }
+  }
+
+  for (auto i: nfa_graph.GetStartVertexes()) {
+    queue.push({i});
+    number_vertex_in_result_tree[{i}] = result_tree.AddNewVertex();
+  }
+
+  while (!queue.empty()) {
+    auto current = queue.front();
+    queue.pop();
+
+    for (auto symbol: alphabet) {
+      std::set<size_t> result;
+      for (auto v: current) {
+        const auto& transitions = nfa_graph.GetVertex(v).GetTransitions();
+        if (transitions.count(symbol)) {
+          const auto& s = transitions.at(symbol);
+          result.insert(s.begin(), s.end());
+        }
+      }
+
+      if (result.size() == 0) continue;
+
+      transitions[std::make_pair(current, symbol)] = result;
+      if (!number_vertex_in_result_tree.count(result)) {
+        queue.push(result);
+        number_vertex_in_result_tree[result] = result_tree.AddNewVertex();
+      }
+    }
+  }
+  
+  for (auto i: transitions) {
+    int v = number_vertex_in_result_tree[i.first.first];
+    int u = number_vertex_in_result_tree[i.second];
+    char symbol = i.first.second;
+    result_tree.GetVertex(v).AddEdge(symbol, u);
+  }
+
+  for (auto i: number_vertex_in_result_tree) {
+    auto s = i.first;
+    auto v = i.second;
+
+    for (auto i: s) {
+      if (nfa_graph.GetVertex(i).IsFinal())
+        result_tree.GetVertex(v).SetFinal(true);
+      if (nfa_graph.GetVertex(i).IsStart())
+        result_tree.GetVertex(v).SetStart(true);
+    }
+  }
+
+  return result_tree;
+}
+
+DFAGraph NFAGraphToDFAGraph(NFAGraph&& nfa_graph) {
+  nfa_graph = DeleteTransitionsByOneLetter(DeleteEpsilonTransitions(AddAllPossibleFinalVertexes(
+      AddAllEpsilonTransitions(std::move(nfa_graph)))));
+
+  const int n = nfa_graph.GetCountVertexes();
+  DFAGraph result;
+  std::map<int, int> number_vertex_in_DFA;
+  for (int i = 0; i < n; ++i) {
+    if (nfa_graph.NotExistVertex(i)) continue;
+    number_vertex_in_DFA[i] = result.AddNewVertex();
+  }
+  bool exists_start_vertex = false;
+  for (int i = 0; i < n; ++i) {
+    if (nfa_graph.NotExistVertex(i)) continue;
+    if (nfa_graph.GetVertex(i).IsFinal())
+      result.GetVertex(number_vertex_in_DFA[i]).SetFinal(true);
+    if (nfa_graph.GetVertex(i).IsStart()) {
+      if (exists_start_vertex) {
+        throw std::runtime_error("I can't delete starts vertex");
+      }
+      result.GetVertex(number_vertex_in_DFA[i]).SetStart(true);
+      exists_start_vertex = true;
+    }
+
+    const auto& transitions = nfa_graph.GetVertex(i).GetTransitions();
+    for (const auto& t: transitions) {
+      if (t.second.size() != 1) throw std::logic_error("");
+      result.GetVertex(number_vertex_in_DFA[i]).AddEdge(t.first, *t.second.begin());
+    }
+  }
+  if (!exists_start_vertex) {
+    throw std::runtime_error("I can't find start vertex");
+  }
+  return result;
+}
+}
diff --git a/src/converters/RegularToNFA.cpp b/src/converters/RegularToNFA.cpp
new file mode 100644
index 0000000..acae0a6
--- /dev/null
+++ b/src/converters/RegularToNFA.cpp
@@ -0,0 +1,87 @@
+#include "converters/RegularToNFA.hpp"
+#include "regular/RegularTree.hpp"
+#include "NFA/NFAGraph.hpp"
+
+using namespace NFA;
+using namespace regular;
+using Node = RegularTree::Node;
+
+struct do_nothing_deleter{
+  template<typename T>
+  void operator()(T*) const {}
+};
+
+template<typename deleter>
+NFAGraph RegularToNFA(std::unique_ptr<Node, deleter> node) {
+  NFAGraph result;
+  if (node->type == Node::Type::Word) {
+    auto end = result.AddNewVertex();
+    auto start = end;
+    result.AddStartVertex(end);
+    for (char i: node->word) {
+      auto tmp = result.AddNewVertex();
+      result.GetVertex(end).AddEdge(i, tmp);
+      end = tmp;
+    }
+    if (node->modifier == Node::Modifier::Plus) {
+      result.GetVertex(end).AddEdge(' ', start);
+    } else if (node->modifier == Node::Modifier::Star) {
+      result.GetVertex(end).AddEdge(' ', start);
+      result.GetVertex(start).AddEdge(' ', end);
+    }
+    result.AddFinalVertex(end);
+  } else if (node->type == Node::Type::Concatenation) {
+    result = RegularToNFA(std::move(node->children[0]));
+    for (auto it = node->children.begin() + 1; it != node->children.end(); ++it) {
+      auto tmp = RegularToNFA(std::move(*it));
+      auto v = result.AddNewVertex();
+      result.Composition(std::move(tmp), result.GetFinalVertexes(), {v});
+      while (!result.GetFinalVertexes().empty()) {
+        result.RemoveFinalVertex(result.GetFinalVertexes()[0]);
+      }
+      result.AddFinalVertex(v);
+    }
+    const auto& start_vertexes = result.GetStartVertexes();
+    const auto& end_vertexes = result.GetFinalVertexes();
+
+    if (node->modifier == Node::Modifier::Plus) {
+      for (auto start: start_vertexes) {
+        for (auto end: end_vertexes) {
+          result.GetVertex(end).AddEdge(' ', start);
+        } 
+      } 
+    } else if (node->modifier == Node::Modifier::Star) {
+      for (auto start: start_vertexes) {
+        for (auto end: end_vertexes) {
+          result.GetVertex(end).AddEdge(' ', start);
+          result.GetVertex(start).AddEdge(' ', end);
+        } 
+      } 
+    }
+    
+  } else if (node->type == Node::Type::Addition) {
+    auto start = result.AddNewVertex();
+    result.AddStartVertex(start);
+    auto end = result.AddNewVertex();
+    result.AddFinalVertex(end);
+    for (auto& i: node->children) {
+      auto tmp = RegularToNFA(std::move(i));
+      result.Composition(std::move(tmp), {start}, {end});
+    }
+    if (node->modifier == Node::Modifier::Plus) {
+      result.GetVertex(end).AddEdge(' ', start);
+    } else if (node->modifier == Node::Modifier::Star) {
+      result.GetVertex(end).AddEdge(' ', start);
+      result.GetVertex(start).AddEdge(' ', end);
+    }
+  }
+  return result;
+}
+
+namespace converters {
+NFAGraph RegularToNFAGraph(RegularTree&& tree) {
+  const Node& root = tree.GetNode();
+  return RegularToNFA(std::unique_ptr<Node,
+                      do_nothing_deleter>(&const_cast<Node&>(tree.GetNode())));
+}
+}
diff --git a/src/main.cpp b/src/main.cpp
index a03be09..9187628 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1,5 +1,108 @@
 #include <iostream>
+#include "regular/RegularTree.hpp"
+#include "NFA/NFAGraph.hpp"
+#include "DFA/DFAGraph.hpp"
+#include "converters/RegularToNFA.hpp"
+#include "converters/NFAToDFA.hpp"
+#include "converters/DFAToFDFA.hpp"
+#include "converters/DFAToMinDFA.hpp"
+#include "converters/DFAToRegular.hpp"
+#include "converters/InvertFDFA.hpp"
+
+using namespace regular;
+using namespace NFA;
+using namespace DFA;
+using namespace converters;
+
+void example1() {
+  RegularTree r("a*");
+  NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));            // Regular to FA
+  DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));   // to DFA
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));        // minimize
+  std::string reg = DFAGraphToRegular(std::move(DFA_graph));      // DFA to regular
+  r = RegularTree(reg);                                           // create regular
+  NFA_tree = RegularToNFAGraph(std::move(r));                     // to FA
+  DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));            // to DFA
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));        // minimize
+  DFA_graph.Print();                                              // print
+}
+
+void example2() {
+  NFAGraph nfa_graph;
+  const size_t N = 10;
+
+  size_t a[N];
+  for (size_t i = 0; i < N; ++i)
+    a[i] = nfa_graph.AddNewVertex();
+
+  auto AddEdge = [&nfa_graph, &a](char symbol, int u, int v) {
+    nfa_graph.GetVertex(a[u]).AddEdge(symbol, a[v]);
+  };
+
+  AddEdge('a', 0, 1);
+  AddEdge('b', 0, 2);
+  AddEdge('b', 1, 3);
+  AddEdge('b', 2, 4);
+
+  DFAGraph dfa_graph = NFAGraphToDFAGraph(std::move(nfa_graph));
+  dfa_graph = DFAGraphToMinDFAGraph(std::move(dfa_graph));
+  dfa_graph.Print();
+}
 
 int main() {
-  std::cout << "hello world";
+  {
+    RegularTree r("a*");
+    NFAGraph NFA_graph = RegularToNFAGraph(std::move(r));
+    DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_graph));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+    DFA_graph = DFAGraphToFDFAGraph(std::move(DFA_graph), {'a', 'b'});
+    DFA_graph.Print();
+    DFA_graph.CreateDotFile("1.dot");
+    DFA_graph = InvertFDFAGraph(std::move(DFA_graph));
+    DFA_graph.CreateDotFile("2.dot");
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+  }
+
+  return 0;
+  {
+    RegularTree r("((ab|ba)*( |a|ba))");
+    NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+    DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    // DFA_graph.CreateDotFile("1.dot");
+    // DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+    DFA_graph = DFAGraphToFDFAGraph(std::move(DFA_graph), {'a', 'b'});
+    DFA_graph = InvertFDFAGraph(std::move(DFA_graph));
+    // DFA_graph.CreateDotFile("2.dot");
+    auto ss = DFAGraphToRegular(std::move(DFA_graph));
+    std::cout << ss << std::endl;
+    r = RegularTree(ss);
+    // r.Print();
+    std::cout << r.ToString() << std::endl;
+    // DFA_graph.Print();
+    return 0;
+
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+    DFA_graph.Print();
+    auto s = DFAGraphToRegular(std::move(DFA_graph));
+    std::cout << s << std::endl;
+    r = RegularTree(s);
+    // r.Print();
+    std::cout << r.ToString() << std::endl;
+  }
+  return 0;
+  RegularTree r("a*");
+  auto nfa = RegularToNFAGraph(std::move(r));
+  auto dfa = NFAGraphToDFAGraph(std::move(nfa));
+  dfa = DFAGraphToMinDFAGraph(std::move(dfa));
+  auto fdfa = DFAGraphToFDFAGraph(std::move(dfa), {'a', 'b'});
+  fdfa.Print();
+  fdfa = InvertFDFAGraph(std::move(fdfa));
+  fdfa.Print();
+  dfa = DFAGraphToMinDFAGraph(std::move(fdfa));
+  auto s = DFAGraphToRegular(std::move(dfa));
+
+  /*
+  RegularTree r("(a|b)+bab(a|b)+");
+  std::cout << DFAGraphToRegular(DFAGraphToMinDFAGraph(InvertFDFAGraph(DFAGraphToFDFAGraph(DFAGraphToMinDFAGraph(NFAGraphToDFAGraph(RegularToNFAGraph(std::move(r)))), {'a', 'b'})))) << std::endl;
+   */
 }
diff --git a/src/regular/RegularTree.cpp b/src/regular/RegularTree.cpp
new file mode 100644
index 0000000..70285b7
--- /dev/null
+++ b/src/regular/RegularTree.cpp
@@ -0,0 +1,19 @@
+#include "regular/RegularTree.hpp"
+
+namespace regular {
+RegularTree::RegularTree(const std::string& regular) {
+  node_.Parse(regular);
+}
+
+const RegularTree::Node& RegularTree::GetNode() const {
+  return node_;
+}
+
+void RegularTree::Print() const {
+  node_.Print();
+}
+
+std::string RegularTree::ToString() const {
+  return node_.ToString();
+}
+}
diff --git a/src/regular/RegularTreeNode.cpp b/src/regular/RegularTreeNode.cpp
new file mode 100644
index 0000000..ac297ae
--- /dev/null
+++ b/src/regular/RegularTreeNode.cpp
@@ -0,0 +1,254 @@
+#include "regular/RegularTree.hpp"
+#include <iostream>
+
+using Node = regular::RegularTree::Node;
+Node::Node() {}
+Node::Node(Type type) : type(type) {}
+
+void Node::Parse(const std::string& regular) {
+  type = Type::Addition;
+  ParseCurrentType(std::string_view(regular.c_str(), regular.size()));
+  for (int i = 0; i < 10; ++i) {
+    Compression();
+    Compression2();
+  }
+}
+
+void Node::Print() const {
+  Print(0);
+}
+
+void Node::ParseCurrentType(const std::string_view regular) {
+  const size_t n = regular.size();
+  children.clear();
+  word.clear();
+
+  auto AddChild = [this](const std::string_view regular) {
+    this->children.push_back(std::make_unique<Node>(Type::Addition));
+    this->children.back()->ParseCurrentType(regular);
+  };
+
+  if (n == 1) {
+    type = Type::Word;
+  }
+
+  if (type == Type::Addition) {
+    int balance = 0;
+    int begin_child = 0;
+    bool wrapped_brackets = (regular[0] == '(');
+
+    for (size_t i = 0; i < n; ++i) {
+      if (regular[i] == '(') {
+        ++balance;
+      } else if (regular[i] == ')') {
+        --balance;
+      }
+
+      if (regular[i] == '|') {
+        if (balance == 0) {
+          AddChild(regular.substr(begin_child + wrapped_brackets, i -
+                                     begin_child - 2 *
+                                     wrapped_brackets));
+          begin_child = i + 1;
+
+          if (i + 1 < n)
+            wrapped_brackets = (regular[i + 1] == '(');
+        }
+      } else {
+        if (i + 1 == n) {
+          if (children.size() == 0) {
+            type = Type::Concatenation;
+            break;
+          } else {
+            AddChild(regular.substr(begin_child + wrapped_brackets, i -
+                                    begin_child + 1 - 2 *
+                                    wrapped_brackets));
+            begin_child = i + 1;
+            if (i + 1 < n)
+              wrapped_brackets = (regular[i + 1] == '(');
+          } 
+        } else if (balance == 0) {
+          wrapped_brackets = false;
+        }
+      } 
+    }
+  }
+
+  if (type == Type::Concatenation) {
+    int balance = 0;
+    int begin_child = 0;
+
+    for (size_t i = 0; i < n; ++i) {
+      if (regular[i] == '(') {
+        ++balance;
+        if (balance == 1) {
+          if (begin_child < i) {
+            AddChild(regular.substr(begin_child, i - begin_child));
+          }
+          begin_child = i + 1;
+        } 
+      } else if (regular[i] == ')') {
+        --balance;
+        if (balance == 0) {
+          AddChild(regular.substr(begin_child, i - begin_child));
+          begin_child = i + 1;
+        }
+      } else if (i + 1 == n) {
+        if (balance != 0) {
+          throw std::logic_error("invalid regular");
+        }
+
+        if (children.size() == 0) {
+          type = Type::Word;
+          break;
+        } else {
+          if (regular[i] == '+') {
+            if (begin_child < i) {
+              AddChild(regular.substr(begin_child, i - begin_child));
+            }
+            children.back()->modifier = Modifier::Plus;
+            begin_child = i + 1;
+          } else if (regular[i] == '*') {
+            if (begin_child < i) {
+              AddChild(regular.substr(begin_child, i - begin_child));
+            }
+            children.back()->modifier = Modifier::Star;
+            begin_child = i + 1;
+          } else {
+            AddChild(regular.substr(begin_child, i - begin_child + 1));
+            begin_child = i + 1;
+          } 
+        } 
+      } else if (balance == 0) {
+        if (regular[i] == '+') {
+          if (begin_child < i) {
+            AddChild(regular.substr(begin_child, i - begin_child));
+          }
+          children.back()->modifier = Modifier::Plus;
+          begin_child = i + 1;
+        } else if (regular[i] == '*') {
+          if (begin_child < i) {
+            AddChild(regular.substr(begin_child, i - begin_child));
+          }
+          children.back()->modifier = Modifier::Star;
+          begin_child = i + 1;
+        }
+      }
+    }
+  }
+
+  if (type == Type::Word) {
+    bool exist_modifire = regular.back() == '+' || regular.back() == '*';
+    if (regular.back() == '+') {
+      modifier = Modifier::Plus;
+    } else if (regular.back() == '*') {
+      modifier = Modifier::Star;
+    }
+    for (size_t i = 0; i < n - exist_modifire; ++i) {
+      if (regular[i] == '|' || regular[i] == '(' || regular[i] == ')') {
+        throw std::logic_error("invalid regular");
+      }
+      word += regular[i];
+    }
+  }
+}
+
+void Node::Compression() {
+  for (auto& i: children) {
+    i->Compression();
+  }
+  if (children.size() == 1 && modifier == Modifier::None) {
+    auto tmp = std::move(*children[0]);
+    *this = std::move(tmp);
+  }
+}
+
+void Node::Compression2() {
+  for (auto& i: children) {
+    i->Compression2();
+  }
+  bool f = type == Type::Concatenation;
+  for (auto& i: children) {
+    f &= i->modifier == Modifier::None;
+    f &= i->type == Type::Word;
+  }
+  if (f) {
+    auto tmp = std::move(*children[0]);
+    tmp.modifier = modifier;
+    for (int i = 1; i < children.size(); ++i) {
+      tmp.word += children[i]->word;
+    }
+    *this = std::move(tmp);
+  }
+}
+
+void Node::Print(int nesting_level) const {
+  auto PrintNesingLevel = [](int nesting_level) {
+    for (int i = 0; i < nesting_level; ++i) {
+      std::cout << "  ";
+    }
+  };
+
+  PrintNesingLevel(nesting_level);
+  if (type == Type::Addition) {
+    std::cout << "Addition";
+    if (modifier == Modifier::Plus) {
+      std::cout << "+";
+    } else if (modifier == Modifier::Star) {
+      std::cout << "*";
+    }
+    std::cout << " " << std::to_string(children.size()) << ":" << std::endl;
+  } else if (type == Type::Concatenation) {
+    std::cout << "Concatenation";
+    if (modifier == Modifier::Plus) {
+      std::cout << "+";
+    } else if (modifier == Modifier::Star) {
+      std::cout << "*";
+    }
+    std::cout << " " << children.size() << ":" << std::endl;
+  } else if (type == Type::Word) {
+    std::cout << "Word";
+    if (modifier == Modifier::Plus) {
+      std::cout << "+";
+    } else if (modifier == Modifier::Star) {
+      std::cout << "*";
+    }
+    std::cout << ": " << word << std::endl;
+  }
+
+  for (const auto& i: children) {
+    i->Print(nesting_level + 1);
+  }
+}
+
+std::string regular::RegularTree::Node::ToString() const {
+  std::string res;
+  if (type == Type::Word) {
+    res = word;
+    if (modifier == Modifier::Plus)
+      res = "(" + res + ")+";
+    else if (modifier == Modifier::Star)
+      res = "(" + res + ")*";
+  } else if (type == Type::Concatenation) {
+    for (auto& i: children) {
+      res += i->ToString();
+    }
+    if (modifier == Modifier::Plus)
+      res = "(" + res + ")+";
+    else if (modifier == Modifier::Star)
+      res = "(" + res + ")*";
+  } else if (type == Type::Addition) {
+    for (auto& i: children) {
+      res += i->ToString();
+      res += "|";
+    }
+    if (res.size())
+      res.pop_back();
+    res = "(" + res + ")";
+    if (modifier == Modifier::Plus)
+      res += "+";
+    else if (modifier == Modifier::Star)
+      res += "*";
+  }
+  return res;
+}
diff --git a/tests/DFAToMinDFA/CountSizesMinDFA.cpp b/tests/DFAToMinDFA/CountSizesMinDFA.cpp
new file mode 100644
index 0000000..66a1cf5
--- /dev/null
+++ b/tests/DFAToMinDFA/CountSizesMinDFA.cpp
@@ -0,0 +1,40 @@
+#include <gtest/gtest.h>
+#include "regular/RegularTree.hpp"
+#include "converters/RegularToNFA.hpp"
+#include "converters/NFAToDFA.hpp"
+#include "converters/DFAToMinDFA.hpp"
+#include "converters/DFAToRegular.hpp"
+
+using namespace regular;
+using namespace NFA;
+using namespace DFA;
+using namespace converters;
+
+size_t GetCountVertexes(const std::string& regular) {
+  RegularTree r(regular);
+  NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+  DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+  return DFA_graph.GetReallyCountVertexes();
+}
+
+TEST(DFA_to_min_DFA, a_start) {
+  EXPECT_EQ(GetCountVertexes("a*"), GetCountVertexes("( a |  )*| |  | aaa a a"));
+}
+
+TEST(DFA_to_min_DFA, a_plus) {
+  EXPECT_EQ(GetCountVertexes("a+"), GetCountVertexes("( a | a a )+|a |  a |a "));
+}
+
+TEST(DFA_to_min_DFA, a_star_or_b_star) {
+  EXPECT_EQ(GetCountVertexes("a*|b*"), GetCountVertexes("a|b|a*|a+|b*|b+|bbb b b b| a a aa a aa | a+"));
+}
+
+TEST(DFA_to_min_DFA, epsilon) {
+  EXPECT_EQ(GetCountVertexes(" "), GetCountVertexes("   |    |    |     "));
+}
+
+TEST(DFA_to_min_DFA, a_or_b_star) {
+  EXPECT_EQ(GetCountVertexes("(a|b)*"), GetCountVertexes("a+|b+|a*|b*|a*b*a*|a|b(a|b)*|b| |(a|b)*"));
+}
diff --git a/tests/DFAToRegular/DFAToRegular.cpp b/tests/DFAToRegular/DFAToRegular.cpp
new file mode 100644
index 0000000..e46e99f
--- /dev/null
+++ b/tests/DFAToRegular/DFAToRegular.cpp
@@ -0,0 +1,202 @@
+#include <gtest/gtest.h>
+#include <random>
+#include "regular/RegularTree.hpp"
+#include "converters/RegularToNFA.hpp"
+#include "converters/NFAToDFA.hpp"
+#include "converters/DFAToMinDFA.hpp"
+#include "converters/DFAToRegular.hpp"
+
+using namespace regular;
+using namespace NFA;
+using namespace DFA;
+using namespace converters;
+
+extern std::mt19937 rnd;
+
+extern std::string GenerateRandomString(std::vector<char> alphabet, size_t len);
+
+TEST(DFA_to_regular, a_star) {
+  RegularTree r("a*");
+  NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+  DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+  std::string reg = DFAGraphToRegular(std::move(DFA_graph));
+
+  r = RegularTree(reg);
+  NFA_tree = RegularToNFAGraph(std::move(r));
+  DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+
+  std::string s = "";
+  for (int i = 0; i < 100; ++i) {
+    ASSERT_EQ(DFA_graph.Accepted(s), true);
+    s += "a";
+  }
+}
+
+TEST(DFA_to_regular, a_plus) {
+  std::string regulars[] = {"a+", "(a)+", "(a+)"};
+  for (const auto& regular: regulars) {
+    RegularTree r(regular);
+    NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+    DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    std::string reg = DFAGraphToRegular(std::move(DFA_graph));
+
+    r = RegularTree(reg);
+    NFA_tree = RegularToNFAGraph(std::move(r));
+    DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    std::string s = "";
+    ASSERT_EQ(DFA_graph.Accepted(s), false);
+    s += "a";
+    for (int i = 0; i < 100; ++i) {
+      ASSERT_EQ(DFA_graph.Accepted(s), true);
+      s += "a";
+    }
+  }
+}
+
+TEST(DFA_to_regular, abc) {
+  std::string regulars[] = {"abc"};
+  for (const auto& regular: regulars) {
+    RegularTree r(regular);
+    NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+    DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    std::string reg = DFAGraphToRegular(std::move(DFA_graph));
+
+    r = RegularTree(reg);
+    NFA_tree = RegularToNFAGraph(std::move(r));
+    DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    ASSERT_EQ(DFA_graph.Accepted("abc"), true);
+    for (int i = 0; i < 1000; ++i) {
+      auto s = GenerateRandomString({'a', 'b', 'c', 'd'}, rnd() % 10);
+      if (s == "abc") continue;
+      ASSERT_EQ(DFA_graph.Accepted(s), false);
+    }
+  }
+}
+
+TEST(DFA_to_regular, a_or_b_or_c) {
+  std::string regulars[] = {};
+  for (const auto& regular: regulars) {
+    RegularTree r("a|b|c");
+    NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+    DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    std::string reg = DFAGraphToRegular(std::move(DFA_graph));
+
+    r = RegularTree(reg);
+    NFA_tree = RegularToNFAGraph(std::move(r));
+    DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    ASSERT_EQ(DFA_graph.Accepted("a"), true);
+    ASSERT_EQ(DFA_graph.Accepted("b"), true);
+    ASSERT_EQ(DFA_graph.Accepted("c"), true);
+    for (int i = 0; i < 1000; ++i) {
+      auto s = GenerateRandomString({'a', 'b', 'c', 'd'}, rnd() % 10);
+      if (s == "a") continue;
+      if (s == "b") continue;
+      if (s == "c") continue;
+      ASSERT_EQ(DFA_graph.Accepted(s), false);
+    }
+  } 
+}
+
+TEST(DFA_to_regular, a_star_or_b_star_or_c_star) {
+  std::string regulars[] = {"a*|b*|c*", "(a*)|(b*|c*)", "(a*|b*|c*)", "((a*)|(b*)|(c*))"};
+  for (const auto& regular: regulars) {
+    RegularTree r(regular);
+    NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+    DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    std::string reg = DFAGraphToRegular(std::move(DFA_graph));
+
+    r = RegularTree(reg);
+    NFA_tree = RegularToNFAGraph(std::move(r));
+    DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    auto check = [](const std::string str) {
+      std::set<char> s(str.begin(), str.end());
+      if (s.size() == 0)
+        return true;
+      else {
+        if (s.size() == 1)
+          return *s.begin() != 'd';
+        else
+          return false;
+      }
+    };
+
+    ASSERT_EQ(DFA_graph.Accepted(""), true);
+    for (int i = 0; i < 1000; ++i) {
+      auto s = GenerateRandomString({'a', 'b', 'c', 'd'}, rnd() % 10);
+
+      ASSERT_EQ(DFA_graph.Accepted(s), check(s));
+    }
+  } 
+}
+
+TEST(DFA_to_regular, _a_star_or_b_star_or_c_star_plus) {
+  RegularTree r("(a*|b*|c*)+");
+  NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+  DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+  std::string reg = DFAGraphToRegular(std::move(DFA_graph));
+
+  r = RegularTree(reg);
+  NFA_tree = RegularToNFAGraph(std::move(r));
+  DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+  auto check = [](const std::string str) {
+    std::set<char> s(str.begin(), str.end());
+    return s.find('d') == s.end();
+  };
+
+  ASSERT_EQ(DFA_graph.Accepted(""), true);
+  for (int i = 0; i < 1000; ++i) {
+    auto s = GenerateRandomString({'a', 'b', 'c', 'd'}, rnd() % 10);
+
+    ASSERT_EQ(DFA_graph.Accepted(s), check(s));
+  }
+}
+
+TEST(DFA_to_regular, _a_or_b_or_c_star_plus) {
+  RegularTree r("(a|b|c*)+");
+  NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+  DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+  std::string reg = DFAGraphToRegular(std::move(DFA_graph));
+
+  r = RegularTree(reg);
+  NFA_tree = RegularToNFAGraph(std::move(r));
+  DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+  auto check = [](const std::string str) {
+    std::set<char> s(str.begin(), str.end());
+    return s.find('d') == s.end();
+  };
+
+  ASSERT_EQ(DFA_graph.Accepted(""), true);
+  for (int i = 0; i < 1000; ++i) {
+    auto s = GenerateRandomString({'a', 'b', 'c', 'd'}, rnd() % 10);
+
+    ASSERT_EQ(DFA_graph.Accepted(s), check(s));
+  }
+}
diff --git a/tests/DFAToRegular/DFAToRegular2.cpp b/tests/DFAToRegular/DFAToRegular2.cpp
new file mode 100644
index 0000000..17603ab
--- /dev/null
+++ b/tests/DFAToRegular/DFAToRegular2.cpp
@@ -0,0 +1,209 @@
+#include <gtest/gtest.h>
+#include <random>
+#include "regular/RegularTree.hpp"
+#include "converters/RegularToNFA.hpp"
+#include "converters/NFAToDFA.hpp"
+#include "converters/DFAToMinDFA.hpp"
+#include "converters/DFAToRegular.hpp"
+
+using namespace regular;
+using namespace NFA;
+using namespace DFA;
+using namespace converters;
+
+extern std::mt19937 rnd;
+
+extern std::string GenerateRandomString(std::vector<char> alphabet, size_t len);
+
+TEST(DFA_to_regular2, a_star) {
+  RegularTree r("a*");
+  NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+  DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+  std::string reg = DFAGraphToRegular(std::move(DFA_graph));
+  reg = RegularTree(reg).ToString();
+
+  r = RegularTree(reg);
+  NFA_tree = RegularToNFAGraph(std::move(r));
+  DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+
+  std::string s = "";
+  for (int i = 0; i < 100; ++i) {
+    ASSERT_EQ(DFA_graph.Accepted(s), true);
+    s += "a";
+  }
+}
+
+TEST(DFA_to_regular2, a_plus) {
+  std::string regulars[] = {"a+", "(a)+", "(a+)"};
+  for (const auto& regular: regulars) {
+    RegularTree r(regular);
+    NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+    DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    std::string reg = DFAGraphToRegular(std::move(DFA_graph));
+    reg = RegularTree(reg).ToString();
+
+    r = RegularTree(reg);
+    NFA_tree = RegularToNFAGraph(std::move(r));
+    DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    std::string s = "";
+    ASSERT_EQ(DFA_graph.Accepted(s), false);
+    s += "a";
+    for (int i = 0; i < 100; ++i) {
+      ASSERT_EQ(DFA_graph.Accepted(s), true);
+      s += "a";
+    }
+  }
+}
+
+TEST(DFA_to_regular2, abc) {
+  std::string regulars[] = {"abc"};
+  for (const auto& regular: regulars) {
+    RegularTree r(regular);
+    NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+    DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    std::string reg = DFAGraphToRegular(std::move(DFA_graph));
+    reg = RegularTree(reg).ToString();
+
+    r = RegularTree(reg);
+    NFA_tree = RegularToNFAGraph(std::move(r));
+    DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    ASSERT_EQ(DFA_graph.Accepted("abc"), true);
+    for (int i = 0; i < 1000; ++i) {
+      auto s = GenerateRandomString({'a', 'b', 'c', 'd'}, rnd() % 10);
+      if (s == "abc") continue;
+      ASSERT_EQ(DFA_graph.Accepted(s), false);
+    }
+  }
+}
+
+TEST(DFA_to_regular2, a_or_b_or_c) {
+  std::string regulars[] = {};
+  for (const auto& regular: regulars) {
+    RegularTree r("a|b|c");
+    NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+    DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    std::string reg = DFAGraphToRegular(std::move(DFA_graph));
+    reg = RegularTree(reg).ToString();
+
+    r = RegularTree(reg);
+    NFA_tree = RegularToNFAGraph(std::move(r));
+    DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    ASSERT_EQ(DFA_graph.Accepted("a"), true);
+    ASSERT_EQ(DFA_graph.Accepted("b"), true);
+    ASSERT_EQ(DFA_graph.Accepted("c"), true);
+    for (int i = 0; i < 1000; ++i) {
+      auto s = GenerateRandomString({'a', 'b', 'c', 'd'}, rnd() % 10);
+      if (s == "a") continue;
+      if (s == "b") continue;
+      if (s == "c") continue;
+      ASSERT_EQ(DFA_graph.Accepted(s), false);
+    }
+  }
+}
+
+TEST(DFA_to_regular2, a_star_or_b_star_or_c_star) {
+  std::string regulars[] = {"a*|b*|c*", "(a*)|(b*|c*)", "(a*|b*|c*)", "((a*)|(b*)|(c*))"};
+  for (const auto& regular: regulars) {
+    RegularTree r(regular);
+    NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+    DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    std::string reg = DFAGraphToRegular(std::move(DFA_graph));
+    reg = RegularTree(reg).ToString();
+
+    r = RegularTree(reg);
+    NFA_tree = RegularToNFAGraph(std::move(r));
+    DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    auto check = [](const std::string str) {
+      std::set<char> s(str.begin(), str.end());
+      if (s.size() == 0)
+        return true;
+      else {
+        if (s.size() == 1)
+          return *s.begin() != 'd';
+        else
+          return false;
+      }
+    };
+
+    ASSERT_EQ(DFA_graph.Accepted(""), true);
+    for (int i = 0; i < 1000; ++i) {
+      auto s = GenerateRandomString({'a', 'b', 'c', 'd'}, rnd() % 10);
+
+      ASSERT_EQ(DFA_graph.Accepted(s), check(s));
+    }
+  }
+}
+
+TEST(DFA_to_regular2, _a_star_or_b_star_or_c_star_plus) {
+  RegularTree r("(a*|b*|c*)+");
+  NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+  DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+  std::string reg = DFAGraphToRegular(std::move(DFA_graph));
+  reg = RegularTree(reg).ToString();
+
+  r = RegularTree(reg);
+  NFA_tree = RegularToNFAGraph(std::move(r));
+  DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+  auto check = [](const std::string str) {
+    std::set<char> s(str.begin(), str.end());
+    return s.find('d') == s.end();
+  };
+
+  ASSERT_EQ(DFA_graph.Accepted(""), true);
+  for (int i = 0; i < 1000; ++i) {
+    auto s = GenerateRandomString({'a', 'b', 'c', 'd'}, rnd() % 10);
+
+    ASSERT_EQ(DFA_graph.Accepted(s), check(s));
+  }
+}
+
+TEST(DFA_to_regular2, _a_or_b_or_c_star_plus) {
+  RegularTree r("(a|b|c*)+");
+  NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+  DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+  std::string reg = DFAGraphToRegular(std::move(DFA_graph));
+  reg = RegularTree(reg).ToString();
+
+  r = RegularTree(reg);
+  NFA_tree = RegularToNFAGraph(std::move(r));
+  DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+  auto check = [](const std::string str) {
+    std::set<char> s(str.begin(), str.end());
+    return s.find('d') == s.end();
+  };
+
+  ASSERT_EQ(DFA_graph.Accepted(""), true);
+  for (int i = 0; i < 1000; ++i) {
+    auto s = GenerateRandomString({'a', 'b', 'c', 'd'}, rnd() % 10);
+
+    ASSERT_EQ(DFA_graph.Accepted(s), check(s));
+  }
+}
diff --git a/tests/test_main.cpp b/tests/MainTest.cpp
similarity index 100%
rename from tests/test_main.cpp
rename to tests/MainTest.cpp
diff --git a/tests/NFAToDFA/CheckEquivalence.cpp b/tests/NFAToDFA/CheckEquivalence.cpp
new file mode 100644
index 0000000..2b84cfa
--- /dev/null
+++ b/tests/NFAToDFA/CheckEquivalence.cpp
@@ -0,0 +1,111 @@
+#include <gtest/gtest.h>
+#include <random>
+#include "DFA/DFAGraph.hpp"
+#include "NFA/NFAGraph.hpp"
+#include "converters/NFAToDFA.hpp"
+
+using namespace NFA;
+using namespace DFA;
+using namespace converters;
+
+std::mt19937 rnd(1337);
+
+std::string GenerateRandomString(std::vector<char> alphabet, size_t len) {
+  std::string res(len, ' ');
+  for (auto& i: res) {
+    i = alphabet[rnd() % alphabet.size()];
+  }
+  return res;
+}
+
+TEST(check_equivalence_NFA_to_DFA, 1) {
+  NFA::NFAGraph tree;
+
+  const int N = 10;
+  int a[N];
+  for (int i = 0; i < N; ++i)
+    a[i] = tree.AddNewVertex();
+
+  tree.GetVertex(a[0]).AddEdge('a', a[1]);
+  tree.GetVertex(a[1]).AddEdge('a', a[2]);
+  tree.GetVertex(a[0]).AddEdge('a', a[3]);
+
+  tree.GetVertex(a[0]).SetStart(true);
+  tree.GetVertex(a[2]).SetFinal(true);
+  tree.GetVertex(a[3]).SetFinal(true);
+
+  DFA::DFAGraph res = converters::NFAGraphToDFAGraph(std::move(tree));
+
+  EXPECT_FALSE(res.Accepted(""));
+  EXPECT_TRUE(res.Accepted("a"));
+  EXPECT_TRUE(res.Accepted("aa"));
+  EXPECT_FALSE(res.Accepted("aaa"));
+  EXPECT_FALSE(res.Accepted("aaaa"));
+  EXPECT_FALSE(res.Accepted("aaaaa"));
+  EXPECT_FALSE(res.Accepted("b"));
+}
+
+TEST(check_equivalence_NFA_to_DFA, 2) {
+  NFA::NFAGraph tree;
+
+  const int N = 10;
+  int a[N];
+  for (int i = 0; i < N; ++i)
+    a[i] = tree.AddNewVertex();
+
+  tree.GetVertex(a[0]).AddEdge('a', a[1]);
+  tree.GetVertex(a[0]).AddEdge('a', a[2]);
+  tree.GetVertex(a[1]).AddEdge('b', a[1]);
+  tree.GetVertex(a[2]).AddEdge('c', a[2]);
+
+  tree.GetVertex(a[0]).SetStart(true);
+  tree.GetVertex(a[1]).SetFinal(true);
+  tree.GetVertex(a[2]).SetFinal(true);
+
+  DFA::DFAGraph res = converters::NFAGraphToDFAGraph(std::move(tree));
+
+  auto check = [](const std::string& str) {
+    if (str.size() > 0) {
+      if (str[0] == 'a') {
+        if (str.size() == 1) {
+          return true;
+        }
+        if (str[1] == 'b') {
+          for (int i = 1; i < str.size(); ++i) {
+            if (str[i] != 'b') {
+              return false;
+            }
+          }
+          return true;
+        }
+        if (str[1] == 'c') {
+          for (int i = 1; i < str.size(); ++i) {
+            if (str[i] != 'c') {
+              return false;
+            }
+          }
+          return true;
+        }
+      }
+    }
+
+    return false;
+  };
+
+  EXPECT_FALSE(res.Accepted(""));
+  EXPECT_TRUE(res.Accepted("a"));
+  EXPECT_FALSE(res.Accepted("aa"));
+  EXPECT_FALSE(res.Accepted("aaa"));
+  EXPECT_FALSE(res.Accepted("aaaa"));
+  EXPECT_FALSE(res.Accepted("aaaaa"));
+  EXPECT_FALSE(res.Accepted("b"));
+  EXPECT_TRUE(res.Accepted("ab"));
+  EXPECT_TRUE(res.Accepted("abb"));
+  EXPECT_TRUE(res.Accepted("ac"));
+  EXPECT_TRUE(res.Accepted("acc"));
+
+  for (int i = 0; i < 5000; ++i) {
+    auto str = GenerateRandomString({'a', 'b', 'c', 'd'}, 20);
+    ASSERT_EQ(res.Accepted(str), check(str));
+  }
+}
diff --git a/tests/invertFDFA/InvertFDFA.cpp b/tests/invertFDFA/InvertFDFA.cpp
new file mode 100644
index 0000000..cc1efb2
--- /dev/null
+++ b/tests/invertFDFA/InvertFDFA.cpp
@@ -0,0 +1,181 @@
+#include <gtest/gtest.h>
+#include <random>
+#include "regular/RegularTree.hpp"
+#include "converters/RegularToNFA.hpp"
+#include "converters/NFAToDFA.hpp"
+#include "converters/DFAToMinDFA.hpp"
+#include "converters/DFAToFDFA.hpp"
+#include "converters/InvertFDFA.hpp"
+
+using namespace regular;
+using namespace NFA;
+using namespace DFA;
+using namespace converters;
+
+extern std::mt19937 rnd;
+
+extern std::string GenerateRandomString(std::vector<char> alphabet, size_t len);
+
+TEST(invert_DFA, a_star) {
+  RegularTree r("a*");
+  NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+  DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+  DFA_graph = DFAGraphToFDFAGraph(std::move(DFA_graph), {'a', 'b', 'c', 'd'});
+  DFA_graph = InvertFDFAGraph(std::move(DFA_graph));
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+  std::string s = "";
+  for (int i = 0; i < 100; ++i) {
+    ASSERT_EQ(DFA_graph.Accepted(s), false);
+    s += "a";
+  }
+}
+
+TEST(invert_DFA, a_plus) {
+  std::string regulars[] = {"a+", "(a)+", "(a+)"};
+  for (const auto& regular: regulars) {
+    RegularTree r(regular);
+    NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+    DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    DFA_graph = DFAGraphToFDFAGraph(std::move(DFA_graph), {'a', 'b', 'c', 'd'});
+    DFA_graph = InvertFDFAGraph(std::move(DFA_graph));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    std::string s = "";
+    ASSERT_EQ(DFA_graph.Accepted(s), true);
+    s += "a";
+    for (int i = 0; i < 100; ++i) {
+      ASSERT_EQ(DFA_graph.Accepted(s), false);
+      s += "a";
+    }
+  }
+}
+
+TEST(invert_DFA, abc) {
+  std::string regulars[] = {"abc"};
+  for (const auto& regular: regulars) {
+    RegularTree r(regular);
+    NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+    DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    DFA_graph = DFAGraphToFDFAGraph(std::move(DFA_graph), {'a', 'b', 'c', 'd'});
+    DFA_graph = InvertFDFAGraph(std::move(DFA_graph));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    ASSERT_EQ(DFA_graph.Accepted("abc"), false);
+    for (int i = 0; i < 1000; ++i) {
+      auto s = GenerateRandomString({'a', 'b', 'c', 'd'}, rnd() % 10);
+      if (s == "abc") continue;
+      ASSERT_EQ(DFA_graph.Accepted(s), true);
+    }
+  }
+}
+
+TEST(invert_DFA, a_or_b_or_c) {
+  std::string regulars[] = {};
+  for (const auto& regular: regulars) {
+    RegularTree r("a|b|c");
+    NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+    DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    DFA_graph = DFAGraphToFDFAGraph(std::move(DFA_graph), {'a', 'b', 'c', 'd'});
+    DFA_graph = InvertFDFAGraph(std::move(DFA_graph));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    ASSERT_EQ(DFA_graph.Accepted("a"), false);
+    ASSERT_EQ(DFA_graph.Accepted("b"), false);
+    ASSERT_EQ(DFA_graph.Accepted("c"), false);
+    for (int i = 0; i < 1000; ++i) {
+      auto s = GenerateRandomString({'a', 'b', 'c', 'd'}, rnd() % 10);
+      if (s == "a") continue;
+      if (s == "b") continue;
+      if (s == "c") continue;
+      ASSERT_EQ(DFA_graph.Accepted(s), true);
+    }
+  }
+}
+
+TEST(invert_DFA, a_star_or_b_star_or_c_star) {
+  std::string regulars[] = {"a*|b*|c*", "(a*)|(b*|c*)", "(a*|b*|c*)", "((a*)|(b*)|(c*))"};
+  for (const auto& regular: regulars) {
+    RegularTree r(regular);
+    NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+    DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    DFA_graph = DFAGraphToFDFAGraph(std::move(DFA_graph), {'a', 'b', 'c', 'd'});
+    DFA_graph = InvertFDFAGraph(std::move(DFA_graph));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    auto check = [](const std::string str) {
+      std::set<char> s(str.begin(), str.end());
+      if (s.size() == 0)
+        return true;
+      else {
+        if (s.size() == 1)
+          return *s.begin() != 'd';
+        else
+          return false;
+      }
+    };
+
+    ASSERT_EQ(DFA_graph.Accepted(""), false);
+    for (int i = 0; i < 1000; ++i) {
+      auto s = GenerateRandomString({'a', 'b', 'c', 'd'}, rnd() % 10);
+
+      ASSERT_EQ(DFA_graph.Accepted(s), !check(s));
+    }
+  }
+}
+
+TEST(invert_DFA, _a_star_or_b_star_or_c_star_plus) {
+  RegularTree r("(a*|b*|c*)+");
+  NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+  DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+  DFA_graph = DFAGraphToFDFAGraph(std::move(DFA_graph), {'a', 'b', 'c', 'd'});
+  DFA_graph = InvertFDFAGraph(std::move(DFA_graph));
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+  auto check = [](const std::string str) {
+    std::set<char> s(str.begin(), str.end());
+    return s.find('d') == s.end();
+  };
+
+  ASSERT_EQ(DFA_graph.Accepted(""), false);
+  for (int i = 0; i < 1000; ++i) {
+    auto s = GenerateRandomString({'a', 'b', 'c', 'd'}, rnd() % 10);
+
+    ASSERT_EQ(DFA_graph.Accepted(s), !check(s));
+  }
+}
+
+TEST(invert_DFA, _a_or_b_or_c_star_plus) {
+  RegularTree r("(a|b|c*)+");
+  NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+  DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+  DFA_graph = DFAGraphToFDFAGraph(std::move(DFA_graph), {'a', 'b', 'c', 'd'});
+  DFA_graph = InvertFDFAGraph(std::move(DFA_graph));
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+  auto check = [](const std::string str) {
+    std::set<char> s(str.begin(), str.end());
+    return s.find('d') == s.end();
+  };
+
+  ASSERT_EQ(DFA_graph.Accepted(""), false);
+  for (int i = 0; i < 1000; ++i) {
+    auto s = GenerateRandomString({'a', 'b', 'c', 'd'}, rnd() % 10);
+
+    ASSERT_EQ(DFA_graph.Accepted(s), !check(s));
+  }
+}
diff --git a/tests/regular/ParseRegular.cpp b/tests/regular/ParseRegular.cpp
new file mode 100644
index 0000000..25bf34a
--- /dev/null
+++ b/tests/regular/ParseRegular.cpp
@@ -0,0 +1,40 @@
+#include <gtest/gtest.h>
+#include "regular/RegularTree.hpp"
+
+using namespace regular;
+
+TEST(parse_regular, only_addition) {
+  RegularTree("a");
+  RegularTree("aa");
+  RegularTree("aaa");
+  RegularTree("aaaa");
+  RegularTree("aaaaa");
+  RegularTree("a|aaaa");
+  RegularTree("a|a|a|a|a");
+  RegularTree("hello|world");
+  RegularTree("qe|wr|lkj|alk");
+}
+
+TEST(parse_regular, only_folding) {
+  RegularTree("(kajfkasf(aksdjf)jka(((aksjdf)K)))jakd");
+  RegularTree("(kajsdfk(aksdjf)kajsdf)kjasdkfja(skdjf(((aksjdkadf)ksjf(kdja))))");
+  RegularTree("((((kdjf))))");
+  RegularTree("kasjf(akjsfkjasdg)kajsdg");
+  RegularTree("akjsdf(akjdf(kdjfak(jkasdf)))");
+  RegularTree("123k4j1k351kk21jkj21k6j2k36j1(((((ajkfajsdfkafdalkdjflk)))))");
+}
+
+TEST(parse_regular, only_modifiers) {
+  RegularTree("jlakjdf*aksdjflaf8*laksfj*lakjsf*alksjdf");
+  RegularTree("jlakjdf*aksdjflaf8+laksfj*lakjsf*alksjdf*");
+  RegularTree("jlakjdf*aksdjflaf8*laksfj*lakjsf+alksjdf");
+  RegularTree("jlakjd+aksdjflaf8*laksfj*lakjsf*alksjdf+");
+}
+
+TEST(parse_regular, all_operations) {
+  RegularTree("(alkjdfaksdf*|lkasdj*|(kasjdf|kajdf*|kjd)*|laksjf*)+");
+  RegularTree("(alkjdfaksdf|lkasdj*|(kas+jdf|kajdf*|kjd)*|laksjf*)+");
+  RegularTree("a|(a|(a|(a|)*))*");
+  RegularTree("kj*|kjadf*|(kajsdf|(kajsd|kjadf|(kasjdf)|kajs)*)*");
+}
+
diff --git a/tests/regularToDFA/RegularToDFA.cpp b/tests/regularToDFA/RegularToDFA.cpp
new file mode 100644
index 0000000..6087923
--- /dev/null
+++ b/tests/regularToDFA/RegularToDFA.cpp
@@ -0,0 +1,151 @@
+#include <gtest/gtest.h>
+#include <random>
+#include "regular/RegularTree.hpp"
+#include "converters/RegularToNFA.hpp"
+#include "converters/NFAToDFA.hpp"
+#include "converters/DFAToMinDFA.hpp"
+
+using namespace regular;
+using namespace NFA;
+using namespace DFA;
+using namespace converters;
+
+extern std::mt19937 rnd;
+
+extern std::string GenerateRandomString(std::vector<char> alphabet, size_t len);
+
+TEST(regular_to_DFA, a_star) {
+  RegularTree r("a*");
+  NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+  DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+  std::string s = "";
+  for (int i = 0; i < 100; ++i) {
+    ASSERT_EQ(DFA_graph.Accepted(s), true);
+    s += "a";
+  }
+}
+
+TEST(regular_to_DFA, a_plus) {
+  std::string regulars[] = {"a+", "(a)+", "(a+)"};
+  for (const auto& regular: regulars) {
+    RegularTree r(regular);
+    NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+    DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    std::string s = "";
+    ASSERT_EQ(DFA_graph.Accepted(s), false);
+    s += "a";
+    for (int i = 0; i < 100; ++i) {
+      ASSERT_EQ(DFA_graph.Accepted(s), true);
+      s += "a";
+    }
+  }
+}
+
+TEST(regular_to_DFA, abc) {
+  std::string regulars[] = {"abc"};
+  for (const auto& regular: regulars) {
+    RegularTree r(regular);
+    NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+    DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    ASSERT_EQ(DFA_graph.Accepted("abc"), true);
+    for (int i = 0; i < 1000; ++i) {
+      auto s = GenerateRandomString({'a', 'b', 'c', 'd'}, rnd() % 10);
+      if (s == "abc") continue;
+      ASSERT_EQ(DFA_graph.Accepted(s), false);
+    }
+  }
+}
+
+TEST(regular_to_DFA, a_or_b_or_c) {
+  std::string regulars[] = {};
+  for (const auto& regular: regulars) {
+    RegularTree r("a|b|c");
+    NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+    DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    ASSERT_EQ(DFA_graph.Accepted("a"), true);
+    ASSERT_EQ(DFA_graph.Accepted("b"), true);
+    ASSERT_EQ(DFA_graph.Accepted("c"), true);
+    for (int i = 0; i < 1000; ++i) {
+      auto s = GenerateRandomString({'a', 'b', 'c', 'd'}, rnd() % 10);
+      if (s == "a") continue;
+      if (s == "b") continue;
+      if (s == "c") continue;
+      ASSERT_EQ(DFA_graph.Accepted(s), false);
+    }
+  } 
+}
+
+TEST(regular_to_DFA, a_star_or_b_star_or_c_star) {
+  std::string regulars[] = {"a*|b*|c*", "(a*)|(b*|c*)", "(a*|b*|c*)", "((a*)|(b*)|(c*))"};
+  for (const auto& regular: regulars) {
+    RegularTree r(regular);
+    NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+    DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+    DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+    auto check = [](const std::string str) {
+      std::set<char> s(str.begin(), str.end());
+      if (s.size() == 0)
+        return true;
+      else {
+        if (s.size() == 1)
+          return *s.begin() != 'd';
+        else
+          return false;
+      }
+    };
+
+    ASSERT_EQ(DFA_graph.Accepted(""), true);
+    for (int i = 0; i < 1000; ++i) {
+      auto s = GenerateRandomString({'a', 'b', 'c', 'd'}, rnd() % 10);
+
+      ASSERT_EQ(DFA_graph.Accepted(s), check(s));
+    }
+  } 
+}
+
+TEST(regular_to_DFA, _a_star_or_b_star_or_c_star_plus) {
+  RegularTree r("(a*|b*|c*)+");
+  NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+  DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+  auto check = [](const std::string str) {
+    std::set<char> s(str.begin(), str.end());
+    return s.find('d') == s.end();
+  };
+
+  ASSERT_EQ(DFA_graph.Accepted(""), true);
+  for (int i = 0; i < 1000; ++i) {
+    auto s = GenerateRandomString({'a', 'b', 'c', 'd'}, rnd() % 10);
+    
+    ASSERT_EQ(DFA_graph.Accepted(s), check(s));
+  }
+}
+
+TEST(regular_to_DFA, _a_or_b_or_c_star_plus) {
+  RegularTree r("(a|b|c*)+");
+  NFAGraph NFA_tree = RegularToNFAGraph(std::move(r));
+  DFAGraph DFA_graph = NFAGraphToDFAGraph(std::move(NFA_tree));
+  DFA_graph = DFAGraphToMinDFAGraph(std::move(DFA_graph));
+
+  auto check = [](const std::string str) {
+    std::set<char> s(str.begin(), str.end());
+    return s.find('d') == s.end();
+  };
+
+  ASSERT_EQ(DFA_graph.Accepted(""), true);
+  for (int i = 0; i < 1000; ++i) {
+    auto s = GenerateRandomString({'a', 'b', 'c', 'd'}, rnd() % 10);
+    
+    ASSERT_EQ(DFA_graph.Accepted(s), check(s));
+  }
+}