Create BFS-ALGORITHM-USING-C++ (#372)

Here's a solution to opened issue BFS algorithm using c++
Please add hacktoberfest tag.

Author: Aman5989

BFS-ALGORITHM-USING-C++

@@ -0,0 +1,72 @@
+// BFS algorithm in C++
+
+#include <iostream>
+#include <list>
+
+using namespace std;
+
+class Graph {
+  int numVertices;
+  list<int>* adjLists;
+  bool* visited;
+
+   public:
+  Graph(int vertices);
+  void addEdge(int src, int dest);
+  void BFS(int startVertex);
+};
+
+// Create a graph with given vertices,
+// and maintain an adjacency list
+Graph::Graph(int vertices) {
+  numVertices = vertices;
+  adjLists = new list<int>[vertices];
+}
+
+// Add edges to the graph
+void Graph::addEdge(int src, int dest) {
+  adjLists[src].push_back(dest);
+  adjLists[dest].push_back(src);
+}
+
+// BFS algorithm
+void Graph::BFS(int startVertex) {
+  visited = new bool[numVertices];
+  for (int i = 0; i < numVertices; i++)
+    visited[i] = false;
+
+  list<int> queue;
+
+  visited[startVertex] = true;
+  queue.push_back(startVertex);
+
+  list<int>::iterator i;
+
+  while (!queue.empty()) {
+    int currVertex = queue.front();
+    cout << "Visited " << currVertex << " ";
+    queue.pop_front();
+
+    for (i = adjLists[currVertex].begin(); i != adjLists[currVertex].end(); ++i) {
+      int adjVertex = *i;
+      if (!visited[adjVertex]) {
+        visited[adjVertex] = true;
+        queue.push_back(adjVertex);
+      }
+    }
+  }
+}
+
+int main() {
+  Graph g(4);
+  g.addEdge(0, 1);
+  g.addEdge(0, 2);
+  g.addEdge(1, 2);
+  g.addEdge(2, 0);
+  g.addEdge(2, 3);
+  g.addEdge(3, 3);
+
+  g.BFS(2);
+
+  return 0;
+}