From 89a2a24f50d76ca1a8d042cd676fc8848d11e7a9 Mon Sep 17 00:00:00 2001
From: stefiosif <stef8iosif@gmail.com>
Date: Tue, 17 May 2022 21:25:47 +0300
Subject: [PATCH] Add decremental maintenance of SCCs frame

---
 algorithm/dmscc.h | 19 +++++++++++++++++++
 graph/graph.h     |  8 ++++++++
 graph/scc.h       | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 74 insertions(+)
 create mode 100644 algorithm/dmscc.h
 create mode 100644 graph/scc.h

diff --git a/algorithm/dmscc.h b/algorithm/dmscc.h
new file mode 100644
index 0000000..4296a86
--- /dev/null
+++ b/algorithm/dmscc.h
@@ -0,0 +1,19 @@
+#ifndef DMSCC_H_
+#define DMSCC_H_
+
+#include "graph/graph.h"
+using namespace graph;
+#include "tarjan.h"
+
+namespace algo {
+
+// A randomized decremental algorithm for maintaining SCCs
+template<typename T>
+class DMSCC {
+public:
+  DMSCC() = default;
+};
+
+}; // namespace algo
+
+#endif
\ No newline at end of file
diff --git a/graph/graph.h b/graph/graph.h
index 2963e6f..7e3ecf2 100644
--- a/graph/graph.h
+++ b/graph/graph.h
@@ -20,6 +20,9 @@ public:
   // Add edge between v and u
   void insert(const T& v, const T& u);
 
+  // Reverse graph directions
+  Graph<T> reverse();
+
   // Adjacency matrix representation
   std::set<T> vertices;
   std::map<T, std::set<T>> adjMatrix;
@@ -37,6 +40,11 @@ void Graph<T>::insert(const T& v, const T& u) {
   adjMatrix[v].insert(u);
 }
 
+template<typename T>
+Graph<T> Graph<T>::reverse() {
+  return Graph<T>();
+}
+
 } // namespace graph
 
 #endif
\ No newline at end of file
diff --git a/graph/scc.h b/graph/scc.h
new file mode 100644
index 0000000..2943c7c
--- /dev/null
+++ b/graph/scc.h
@@ -0,0 +1,47 @@
+#ifndef SCC_H_
+#define SCC_H_
+
+#include "graph/graph.h"
+
+namespace graph {
+
+template<typename T>
+class SCC {
+public:
+  SCC(std::vector<T> scc);
+
+  // Construct shortest path
+  std::vector<T> SPT();
+
+  // Convert SCC into a Graph
+  Graph<T> convert();
+private:
+  std::vector<T> scc;
+  // Representative - Root(SPT) of this SCC
+  T root;
+};
+
+template<typename T>
+SCC<T>::SCC(std::vector<T> component) {
+  scc = component;
+  root = scc[0];
+}
+
+template<typename T>
+std::vector<T> SCC<T>::SPT() {
+  
+  // BFS
+  
+  return std::vector<T>();
+}
+
+template<typename T>
+Graph<T> SCC<T>::convert() {
+
+
+  return Graph<T>();
+}
+
+}; // namespace graph
+
+#endif
\ No newline at end of file