diff --git a/include/algorithm/decremental_reachability.h b/include/algorithm/decremental_reachability.h
index 1258a6c..c09ffcb 100644
--- a/include/algorithm/decremental_reachability.h
+++ b/include/algorithm/decremental_reachability.h
@@ -8,7 +8,7 @@ namespace algo {
 template<typename T>
 class DecrementalReachability {
 public:
-  virtual ~DecrementalReachability() {};
+  virtual ~DecrementalReachability() = default;
 
   // This method is implemented and executed by all roditty and zwick
   // algorithms, it constructs the data structures used in other operations
diff --git a/include/algorithm/frigioni.h b/include/algorithm/frigioni.h
index bd5102f..933c42e 100644
--- a/include/algorithm/frigioni.h
+++ b/include/algorithm/frigioni.h
@@ -6,8 +6,6 @@
 
 #include <utility>
 
-using namespace graph;
-
 namespace algo {
 
 template<typename T>
@@ -15,7 +13,7 @@ class Frigioni : public DecrementalReachability<T> {
 public:
   Frigioni() = default;
 
-  Frigioni(Digraph<T> G) { this->G = G; }
+  explicit Frigioni(graph::Digraph<T> G) { this->G = G; }
 
   // Initialize the decremental maintenance data structure for general graphs
   void init() override;
diff --git a/include/algorithm/henzinger_king.h b/include/algorithm/henzinger_king.h
index 2fd5c2d..95031a8 100644
--- a/include/algorithm/henzinger_king.h
+++ b/include/algorithm/henzinger_king.h
@@ -4,8 +4,6 @@
 #include "algorithm/dynamic_reachability.h"
 #include "algorithm/frigioni.h"
 
-using namespace graph;
-
 constexpr int threshold = 5;
 
 namespace algo {
@@ -15,7 +13,7 @@ class HenzingerKing : public DynamicReachability<T> {
 public:
   HenzingerKing() = default;
 
-  HenzingerKing(Digraph<T> G) { this->G = G; }
+  explicit HenzingerKing(graph::Digraph<T> G) { this->G = G; }
 
   // Initialize decremental maintenance data structure and the empty set S
   void init() override;
@@ -57,7 +55,7 @@ bool HenzingerKing<T>::query(const T& u, const T& v) {
   if (frigioni.query(u, v))
     return true;
 
-  return std::any_of(S.begin(), S.end(),
+  return std::ranges::any_of(S.begin(), S.end(),
                      [&](const T& w) {
                        return In[w].adjList.contains(u) &&
                          Out[w].adjList.contains(v);
diff --git a/include/algorithm/italiano.h b/include/algorithm/italiano.h
index fc16aa0..ad6083d 100644
--- a/include/algorithm/italiano.h
+++ b/include/algorithm/italiano.h
@@ -6,8 +6,6 @@
 
 #include <stack>
 
-using namespace graph;
-
 namespace algo {
 
 template<typename T>
@@ -15,7 +13,7 @@ class Italiano : public DecrementalReachability<T> {
 public:
   Italiano() = default;
 
-  Italiano(Digraph<T> G) { this->G = G; }
+  explicit Italiano(graph::Digraph<T> G) { this->G = G; }
 
   // Initialize the decremental maintenance data structure for DAGs
   void init() override;
diff --git a/include/algorithm/king.h b/include/algorithm/king.h
index 12040d3..8681253 100644
--- a/include/algorithm/king.h
+++ b/include/algorithm/king.h
@@ -4,8 +4,6 @@
 #include "algorithm/dynamic_reachability.h"
 #include "algorithm/italiano.h"
 
-using namespace graph;
-
 namespace algo {
 
 template<typename T>
@@ -13,7 +11,7 @@ class King : public DynamicReachability<T> {
 public:
   King() = default;
 
-  King(Digraph<T> G) { this->G = G; }
+  explicit King(graph::Digraph<T> G) { this->G = G; }
 
   // Initialize decremental maintenance data structures for DAGs for each
   // vertex's in and out reachability trees
@@ -50,7 +48,7 @@ void King<T>::init() {
 
 template<typename T>
 bool King<T>::query(const T& u, const T& v) {
-  return std::any_of(this->G.vertices().begin(), this->G.vertices().end(),
+  return std::ranges::any_of(this->G.vertices().begin(), this->G.vertices().end(),
                      [&](const T& w) {
                        return In[w].query(w, u) && Out[w].query(w, v);
                      });
diff --git a/include/algorithm/roditty_zwick.h b/include/algorithm/roditty_zwick.h
index 7e71e33..e6f1b67 100644
--- a/include/algorithm/roditty_zwick.h
+++ b/include/algorithm/roditty_zwick.h
@@ -5,8 +5,6 @@
 #include "algorithm/tarjan.h"
 #include "graph/breadth_first_tree.h"
 
-using namespace graph;
-
 namespace algo {
 
 template<typename T>
@@ -14,7 +12,7 @@ class RodittyZwick : public DecrementalReachability<T> {
 public:
   RodittyZwick() = default;
 
-  RodittyZwick(Digraph<T> G) { this->G = G; }
+  explicit RodittyZwick(graph::Digraph<T> G) { this->G = G; }
 
   //
   void init() override;
diff --git a/include/algorithm/tarjan.h b/include/algorithm/tarjan.h
index 018a8c8..9501548 100644
--- a/include/algorithm/tarjan.h
+++ b/include/algorithm/tarjan.h
@@ -7,8 +7,6 @@
 #include <vector>
 #include <ranges>
 
-using namespace graph;
-
 namespace algo {
 
 template<typename T>
@@ -16,7 +14,7 @@ class Tarjan {
 public:
   Tarjan() = default;
 
-  Tarjan(std::unordered_map<T, std::unordered_set<T>> adjList) : adjList(adjList) {}
+  explicit Tarjan(std::unordered_map<T, std::unordered_set<T>> adjList) : adjList(adjList) {}
 
   //
   auto execute();
@@ -27,7 +25,7 @@ private:
   std::unordered_map<T, std::unordered_set<T>> adjList;
   std::stack<T> S;
   std::int16_t index = 0;
-  std::vector<SCC<T>> SCCs;
+  std::vector<graph::SCC<T>> SCCs;
   T cid;
 
   struct Vertex {
diff --git a/include/graph/digraph.h b/include/graph/digraph.h
index 4c2689e..371659a 100644
--- a/include/graph/digraph.h
+++ b/include/graph/digraph.h
@@ -11,7 +11,7 @@ class Digraph : public Graph<T> {
 public:
   Digraph() = default;
 
-  Digraph(std::unordered_map<T, std::unordered_set<T>> G);
+  explicit Digraph(std::unordered_map<T, std::unordered_set<T>> G);
 
   // Return true if there is a path from u to v
   bool contains(const T& u, const T& v);
diff --git a/include/graph/graph.h b/include/graph/graph.h
index 3968c8d..c30462b 100644
--- a/include/graph/graph.h
+++ b/include/graph/graph.h
@@ -15,7 +15,7 @@ template<typename T> std::ostream& operator<<(std::ostream& os, Graph<T>& G);
 template<typename T>
 class Graph {
 public:
-  ~Graph();
+  virtual ~Graph() = default;
   
   // Return true if there is a path from u to v
   virtual bool contains(const T& u, const T& v) =0;
@@ -41,11 +41,6 @@ public:
   friend std::ostream& operator<<<>(std::ostream& os, Graph<T>& G);
 };
 
-template<typename T>
-Graph<T>::~Graph() {
-  adjList.clear();
-}
-
 template<typename T>
 auto Graph<T>::vertices() {
   return std::views::keys(adjList);
@@ -62,7 +57,7 @@ std::uint16_t Graph<T>::E() {
   for (const auto& u : vertices()) {
     edges += static_cast<std::uint16_t>(adjList[u].size());
   }
-  return static_cast<std::uint16_t>(edges);
+  return edges;
 }
 
 template<typename T>