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

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);
                      });