From d199b7de1753b47cb749b90213ecf46a15779418 Mon Sep 17 00:00:00 2001
From: stefiosif <stef8iosif@gmail.com>
Date: Wed, 29 Jun 2022 17:33:27 +0300
Subject: [PATCH] Add tests for same SCC O(1) query

---
 algorithm/decremental_scc.h | 10 +++++-----
 algorithm/tarjan.h          |  4 ++--
 test/algorithm_test.cc      | 16 ++++++++++++++--
 test/graph_test.cc          |  4 ++--
 4 files changed, 23 insertions(+), 11 deletions(-)

diff --git a/algorithm/decremental_scc.h b/algorithm/decremental_scc.h
index 6c018dc..6cc447c 100644
--- a/algorithm/decremental_scc.h
+++ b/algorithm/decremental_scc.h
@@ -36,14 +36,14 @@ private:
   std::map<T, std::pair<Digraph<T>, Digraph<T>>> SPT;
 
   // Connect each representative with its SCC
-  std::map<T, SCC<T>> SCCs;
+  std::map<T, SCC<T>> connection;
 };
 
 template<typename T>
 void DecrementalSCC<T>::init() {
-  auto tarjan = Tarjan<T>(G).run();
+  auto SCCs = Tarjan<T>(G).findSCC();
 
-  for (auto& C : tarjan) {
+  for (auto& C : SCCs) {
     const auto& w = C.representative();
 
     // Create shortest-paths out-tree/in-tree
@@ -55,7 +55,7 @@ void DecrementalSCC<T>::init() {
       A[v] = w;
 
     // Link SCC with its representative w
-    SCCs[w] = C;
+    connection[w] = C;
   }
 }
 
@@ -77,7 +77,7 @@ void DecrementalSCC<T>::remove(const T& u, const T& v) {
     return;
 
   // Update In(w) and Out(w)
-  auto inTree = BFS<T>(SCCs[w]).run(w);
+  auto inTree = BFS<T>(connection[w]).run(w);
   SPT[w] = std::make_pair(inTree, inTree.reverse());
 
   if (!SPT[w].second.vertices.contains(u) ||
diff --git a/algorithm/tarjan.h b/algorithm/tarjan.h
index 06bd8ab..80fbc83 100644
--- a/algorithm/tarjan.h
+++ b/algorithm/tarjan.h
@@ -17,7 +17,7 @@ public:
   Tarjan(Digraph<T> G) : G(G) {}
 
   //
-  std::vector<SCC<T>> run();
+  std::vector<SCC<T>> findSCC();
 
   //
   void strongConnect(const T& v);
@@ -68,7 +68,7 @@ void Tarjan<T>::strongConnect(const T& v) {
 }
 
 template<typename T>
-std::vector<SCC<T>> Tarjan<T>::run() {
+std::vector<SCC<T>> Tarjan<T>::findSCC() {
   for (const auto& v : G.vertices) {
     if (p[v].index == -1) {
       strongConnect(v);
diff --git a/test/algorithm_test.cc b/test/algorithm_test.cc
index 2f64fec..c5477fb 100644
--- a/test/algorithm_test.cc
+++ b/test/algorithm_test.cc
@@ -30,7 +30,7 @@ TEST_SUITE("Algorithm") {
     REQUIRE_EQ(G.vertices.size(), 9);
 
     algo::Tarjan<std::uint16_t> tarjan(G);
-    auto res = tarjan.run();
+    auto res = tarjan.findSCC();
 
     std::vector<std::vector<std::uint16_t>> exp = {
       {6, 8, 9},
@@ -63,7 +63,7 @@ TEST_SUITE("Algorithm") {
     REQUIRE_EQ(G.vertices.size(), 7);
 
     algo::Tarjan<std::uint16_t> tarjan(G);
-    auto res = tarjan.run();
+    auto res = tarjan.findSCC();
 
     std::vector<std::vector<std::uint16_t>> exp = {
       {2, 5, 7},
@@ -133,6 +133,18 @@ TEST_SUITE("Algorithm") {
     algo::DecrementalSCC<std::uint16_t> rz(G);
     rz.init();
 
+    std::vector<std::vector<std::uint16_t>> exp = {
+      {2, 5, 7},
+      {1, 3, 4, 6}
+    };
+
+    CHECK_EQ(rz.query(1, 2), false);
+    CHECK_EQ(rz.query(1, 3), true);
+    CHECK_EQ(rz.query(1, 7), false);
+    CHECK_EQ(rz.query(2, 3), false);
+    CHECK_EQ(rz.query(2, 5), true);
+    CHECK_EQ(rz.query(5, 7), true);
+
     //CHECK_EQ(rz.query(1, 2), true);
   }
 }
\ No newline at end of file
diff --git a/test/graph_test.cc b/test/graph_test.cc
index 0c22b3c..c6a380e 100644
--- a/test/graph_test.cc
+++ b/test/graph_test.cc
@@ -67,7 +67,7 @@ TEST_SUITE("Graph") {
     REQUIRE_EQ(G.vertices.size(), 9);
 
     algo::Tarjan<std::uint16_t> tarjan(G);
-    auto sccs = tarjan.run();
+    auto sccs = tarjan.findSCC();
   }
 
   TEST_CASE("SCC T2") {
@@ -88,6 +88,6 @@ TEST_SUITE("Graph") {
     REQUIRE_EQ(G.vertices.size(), 7);
 
     algo::Tarjan<std::uint16_t> tarjan(G);
-    auto sccs = tarjan.run();
+    auto sccs = tarjan.findSCC();
   }
 }
\ No newline at end of file