From 6392099cab71da02f8cf3a525d33c1c2c276a9c3 Mon Sep 17 00:00:00 2001
From: Ayaan Khan <ayaankhan98@gmail.com>
Date: Mon, 18 May 2020 16:14:51 +0530
Subject: [PATCH] Connected Components using DFS

---
 graph/connected_components.cpp | 61 ++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)
 create mode 100644 graph/connected_components.cpp

diff --git a/graph/connected_components.cpp b/graph/connected_components.cpp
new file mode 100644
index 000000000..4df4fb7c6
--- /dev/null
+++ b/graph/connected_components.cpp
@@ -0,0 +1,61 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+class graph
+{
+  private:
+    vector<vector<int>> adj;
+    int cc;
+    void dfs();
+    void explore(int, vector<bool>&);
+  public:
+    graph(int n): adj(n,vector<int>()), cc(0) {}
+    void addEdge(int,int);
+    int getConnectedComponents()
+    {
+      dfs();
+      return cc;
+    }
+};
+
+void graph::addEdge(int u, int v)
+{
+  adj[u-1].push_back(v-1);
+  adj[v-1].push_back(u-1);
+}
+
+void graph::dfs()
+{
+  int n = adj.size();
+  vector<bool> visited(n,false);
+
+  for(int i = 0;i<n;i++)
+  {
+    if (!visited[i])
+    {
+      explore(i,visited);
+      cc++;
+    }
+  }
+}
+
+void graph::explore(int u, vector<bool> &visited)
+{
+  visited[u] = true;
+  for(auto v : adj[u])
+  {
+    if(!visited[v])
+      explore(v,visited);
+  }
+}
+
+int main()
+{
+  graph g(4);
+  g.addEdge(1,2);
+  g.addEdge(3,2);
+  cout<<g.getConnectedComponents();
+  return 0;
+}