Remove "using namespace" from headers and make single param constructors explicit

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);