Fix includes and add some comments

algorithm/decremental_scc.h

@@ -1,11 +1,10 @@
 #ifndef DECREMENTAL_SCC_H_
 #define DECREMENTAL_SCC_H_
 
-#include "graph/digraph.h"
-#include "graph/scc.h"
-#include "algorithm/tarjan.h"
-#include "algorithm/bfs.h"
 #include "algorithm/roditty_zwick.h"
+#include "algorithm/tarjan.h"
+#include "algorithm/breadth_first_search.h"
+#include "tree/breadth_first_tree.h"
 
 using namespace graph;
 
@@ -16,16 +15,12 @@ class DecrementalSCC : public RodittyZwick<T> {
 public:
   DecrementalSCC(Digraph<T> G) : G(G) {}
 
-  //
   void init();
 
-  //
   void findSCC();
 
-  //
   bool query(const T& u, const T& v);
 
-  //
   void remove(const T& u, const T& v);
 private:
   Digraph<T> G;
@@ -49,13 +44,13 @@ void DecrementalSCC<T>::init() {
 
 template<typename T>
 void DecrementalSCC<T>::findSCC() {
-  auto SCCs = Tarjan<T>(G).findSCC();
+  auto SCCs = Tarjan<T>(G).execute();
 
   for (auto& C : SCCs) {
     const auto& w = C.representative();
 
     // Create shortest-paths out-tree/in-tree
-    auto outTree = Digraph<T>(BFS<T>(C).run(w));
+    auto outTree = Digraph<T>(BreadthFirstSearch<T>(C).execute(w));
     SPT[w] = std::make_pair(outTree, outTree.reverse());
 
     // Update A with current SCCs vertices
@@ -89,7 +84,7 @@ void DecrementalSCC<T>::remove(const T& u, const T& v) {
   // Update In(w) and Out(w)
   connection[w].adjMatrix[u].erase(v);
   G.adjMatrix[u].erase(v);
-  auto inTree = Digraph<T>(BFS<T>(connection[w]).run(w));
+  auto inTree = Digraph<T>(BreadthFirstSearch<T>(connection[w]).execute(w));
   SPT[w] = std::make_pair(inTree, inTree.reverse());
 
   // If a SCC is broken, compute all SCCs again

algorithm/decremental_tc.h

@@ -1,11 +1,14 @@
 #ifndef DECREMENTAL_TC_H_
 #define DECREMENTAL_TC_H_
 
-#include "graph/digraph.h"
-#include "graph/scc.h"
-#include "algorithm/tarjan.h"
-#include "algorithm/bfs.h"
 #include "algorithm/roditty_zwick.h"
+#include "algorithm/tarjan.h"
+#include "algorithm/breadth_first_search.h"
+#include "tree/breadth_first_tree.h"
+
+#include <forward_list>
+
+using namespace graph;
 
 namespace algo {
 
@@ -14,14 +17,21 @@ class DecrementalTC : public RodittyZwick<T> {
 public:
   DecrementalTC(Digraph<T> G) : G(G) {}
 
-  //
   void init();
 
-  //
   bool query(const T& u, const T& v);
 
-  //
   void remove(const T& u, const T& v);
+private:
+  // Every vertex u has a pointer C(u) to the component containing it
+  std::map<T, T> vc;
+
+  // For every component C, the algorithm maintains three linked lists
+  // Ein(C), Eout(C), and Eint(C) of the incoming, outgoing, and the internal
+  // edges of the component C
+  std::forward_list<T> Ein;
+  std::forward_list<T> Eout;
+  std::forward_list<T> Eint;
 };
 
 

algorithm/dynamic_reachability.h

@@ -1,31 +1,16 @@
 #ifndef DYNAMIC_REACHABILITY_
 #define DYNAMIC_REACHABILITY_
 
-#include "graph/digraph.h"
-#include "graph/scc.h"
-#include "algorithm/tarjan.h"
-#include "algorithm/bfs.h"
 #include "algorithm/roditty_zwick.h"
 
-using namespace graph;
-
 namespace algo {
 
 template<typename T>
 class DynamicReachability : public RodittyZwick {
   ~DynamicReachability();
 
-  //
+  // Insert edge e(u,v) and maintain the transitive closure matrix
-  virtual void init() =0;
+  virtual void insert(const T& u, const T& v) =0;
-
-  //
-  virtual bool query(const T& u, const T& v) =0;
-
-  //
-  virtual void remove(const T& u, const T& v) =0;
-
-  //
-  virtual void insert() =0;
 };
 
 template<typename T>

algorithm/roditty_zwick.h

@@ -1,8 +1,6 @@
 #ifndef RODITTY_ZWICK_H_
 #define RODITTY_ZWICK_H_
 
-using namespace graph;
-
 namespace algo {
 
 template<typename T>
@@ -10,13 +8,14 @@ class RodittyZwick {
 public:
   ~RodittyZwick();
 
-  //
+  // This method is implemented and executed by all roditty and zwick
+  // algorithms, it constructs the data structures used in other operations
   virtual void init() =0;
 
-  //
+  // Answer if vertex v is reachable from vertex u
   virtual bool query(const T& u, const T& v) =0;
 
-  //
+  // Remove edge e(u,v) and maintain the transitive closure matrix
   virtual void remove(const T& u, const T& v) =0;
 };
 

algorithm/tarjan.h

@@ -1,7 +1,6 @@
 #ifndef TARJAN_H_
 #define TARJAN_H_
 
-#include "graph/digraph.h"
 #include "graph/scc.h"
 
 #include <stack>
@@ -16,10 +15,8 @@ class Tarjan {
 public:
   Tarjan(Digraph<T> G) : G(G) {}
 
-  //
+  std::vector<SCC<T>> execute();
-  std::vector<SCC<T>> findSCC();
 
-  //
   void strongConnect(const T& v);
 private:
   // Necessary info about vertices when running Tarjan's algorithm
@@ -68,7 +65,7 @@ void Tarjan<T>::strongConnect(const T& v) {
 }
 
 template<typename T>
-std::vector<SCC<T>> Tarjan<T>::findSCC() {
+std::vector<SCC<T>> Tarjan<T>::execute() {
   for (const auto& v : G.vertices) {
     if (p[v].index == -1) {
       strongConnect(v);

graph/scc.h

@@ -21,7 +21,6 @@ private:
   // Each SCC has a representative vertex that helps
   // answer strong connectivity queries in O(1) time
   T proxy;
-
 };
 
 }; // namespace graph

graph/transitive_closure.h

@@ -1,18 +0,0 @@
-#ifndef TRANSITIVE_CLOSURE_H_
-#define TRANSITIVE_CLOSURE_H_
-
-#include "digraph.h"
-
-namespace graph {
-
-// Transitive closure matrix class to answer reachability queries
-template<typename T>
-class TransitiveClosure {
-public:
-  TransitiveClosure() = default;
-};
-
-} // namespace graph
-
-
-#endif