Improve readability

include/algorithm/italiano.h

@@ -3,7 +3,6 @@
 
 #include "algorithm/decremental_reachability.h"
 #include "graph/breadth_first_tree.h"
-
 #include <stack>
 
 namespace algo {
@@ -25,7 +24,7 @@ public:
   // Delete collection of edges
   void remove(const std::vector<std::pair<T, T>>& edges) override;
 
-  // Delete edge e(u, v) and explicitely maintain the transitive closure
+  // Delete edge e(u, v) and explicitly maintain the transitive closure
   void remove(const T& u, const T& v);
 private:
   // Transitive closure matrix
@@ -41,8 +40,11 @@ private:
   };
   std::unordered_map<T, Edges> E;
 
+  //
+  std::unordered_map<T, std::stack<T>> H;
+
   // Repair reachability trees after edge deletions
-  void repairTrees(std::unordered_map<T, std::stack<T>>& H);
+  void repairTrees();
 };
 
 template<typename T>
@@ -67,53 +69,54 @@ bool Italiano<T>::query(const T& u, const T& v) {
 
 template<typename T>
 void Italiano<T>::remove(const std::vector<std::pair<T, T>>& edges) {
-  for (const auto& [u, v] : edges)
+  for (const auto& [u, v] : edges) {
+    if (!this->G.adjList[u].contains(v)) continue;
     remove(u, v);
+  }
 }
 
 template<typename T>
 void Italiano<T>::remove(const T& u, const T& v) {
-  if (!this->G.adjList[u].contains(v)) return;
-
-  std::unordered_map<T, std::stack<T>> H;
-  for (const auto& w : this->G.vertices()) {
-    if (RT[w].contains(u, v)) {
-      if (E[v].inc.size() > 1)
-        H[w].push(v);
-      else {
-        TC[w][v] = false;
-        for (const auto& c : E[v].out)
-          H[w].push(c);
-      }
-      RT[w].adjList[u].erase(v);
-    }
-  }
+  this->G.remove(u, v);
   E[u].out.erase(v);
   E[v].inc.erase(u);
-  this->G.remove(u, v);
+  
+  for (const auto& w : this->G.vertices()) {
+    if (!RT[w].adjList[u].contains(v)) continue;
 
-  repairTrees(H);
+    RT[w].adjList[u].erase(v);
+    if (E[v].inc.size() > 0) {
+      H[w].push(v);
+      continue;
+    }
+    TC[w][v] = false;
+    for (const auto& c : E[v].out)
+      H[w].push(c);
+  }
+  repairTrees();
 }
 
 template<typename T>
-void Italiano<T>::repairTrees(std::unordered_map<T, std::stack<T>>& H) {
-  for (const auto& z : this->G.vertices()) {
-    while (H[z].size() > 0) {
-      const auto& h = H[z].top();
-      bool found = false;
+void Italiano<T>::repairTrees() {
+  for (const auto& w : this->G.vertices()) {
+    while (H[w].size() > 0) {
+      const auto& h = H[w].top();
+      H[w].pop();
+      bool foundHook = false;
 
       for (const auto& i : E[h].inc) {
-        if (RT[z].contains(z, i)) {
-          RT[z].adjList[i].insert(h);
-          found = true;
+        if (RT[w].adjList[w].contains(i)) {
+          RT[w].adjList[i].insert(h);
+          foundHook = true;
           break;
         }
       }
-      H[z].pop();
-      if (!found) {
-        TC[z][h] = false;
-        for (const auto& o : E[h].out) {
-          H[z].push(o);
+      if (foundHook) continue;
+
+      TC[w][h] = false;
+      for (const auto& o : E[h].out) {
+        if (RT[w].adjList[h].contains(o)) {
+          H[w].push(o);
         }
       }
     }