DFS-starter

// C++ program to print DFS traversal from
// a given vertex in a  given graph
#include <bits/stdc++.h>
using namespace std;
  
// Graph class represents a directed graph
// using adjacency list representation
class Graph 
{
public:
    map<int, bool> visited;
    map<int, list<int>> adj;
  
    // function to add an edge to graph
    void addEdge(int v, int w);
  
    // DFS traversal of the vertices
    // reachable from v
    void DFS(int v);
};
  
void Graph::addEdge(int v, int w)
{
    adj[v].push_back(w); // Add w to v’s list.
}
  
void Graph::DFS(int v)
{
    // Mark the current node as visited and
    // print it
    visited[v] = true;
    cout << v << " ";
  
    // Recur for all the vertices adjacent
    // to this vertex
    list<int>::iterator i;
    for (i = adj[v].begin(); i != adj[v].end(); ++i)
        if (!visited[*i])
            DFS(*i);
}
  
// Driver code
int main()
{
    // Create a graph given in the above diagram
    Graph g;
    g.addEdge(0, 1);
    g.addEdge(0, 2);
    g.addEdge(1, 2);
    g.addEdge(2, 0);
    g.addEdge(2, 3);
    g.addEdge(3, 3);
  
    cout << "Following is Depth First Traversal"
            " (starting from vertex 2) \n";
    g.DFS(2);
  
    return 0;
}

// C++ program to print DFS
// traversal for a given given
// graph
#include <bits/stdc++.h>
using namespace std;
  
class Graph {
  
    // A function used by DFS
    void DFSUtil(int v);
  
public:
    map<int, bool> visited;
    map<int, list<int>> adj;
    // function to add an edge to graph
    void addEdge(int v, int w);
  
    // prints DFS traversal of the complete graph
    void DFS();
};
  
void Graph::addEdge(int v, int w)
{
    adj[v].push_back(w); // Add w to v’s list.
}
  
void Graph::DFSUtil(int v)
{
    // Mark the current node as visited and print it
    visited[v] = true;
    cout << v << " ";
  
    // Recur for all the vertices adjacent to this vertex
    list<int>::iterator i;
    for (i = adj[v].begin(); i != adj[v].end(); ++i)
        if (!visited[*i])
            DFSUtil(*i);
}
  
// The function to do DFS traversal. It uses recursive
// DFSUtil()
void Graph::DFS()
{
    // Call the recursive helper function to print DFS
    // traversal starting from all vertices one by one
    for (auto i:adj)
        if (visited[i.first] == false)
            DFSUtil(i.first);
}
  
// Driver  Code
int main()
{
    // Create a graph given in the above diagram
    Graph g;
    g.addEdge(0, 1);
    g.addEdge(0, 9);
    g.addEdge(1, 2);
    g.addEdge(2, 0);
    g.addEdge(2, 3);
    g.addEdge(9, 3);
  
    cout << "Following is Depth First Traversal \n";
    g.DFS();
  
    return 0;
}