Solution Review: Find a "Mother Vertex" in a Graph

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace chapter_5
{
    class Challenge_4_1
    {
        static int performDFS(Graph g, int source) {
    int num_of_vertices = g.getVertices();
    int vertices_reached = 0; //To store how many vertices reached starting from source
    //Bool Array to hold the history of visited nodes
    //Make a node visited whenever you push it into stack
    bool [] visited = new bool[num_of_vertices];
    //Create Stack(Implemented in previous lesson) for Depth First Traversal and Push source in it
    Stack <int>stack = new  Stack<int>();
    stack.Push(source);
    visited[source] = true;
    //Traverse while stack is not empty
    int current_node;
   
    while (stack.Count != 0) {
        //Pop a vertex/node from stack
        current_node = stack.Pop();
        //Get adjacent vertices to the current_node from the array,
        //and if only push unvisited adjacent vertices into stack
        LinkedList.Node temp = (g.getArray())[current_node].GetHead();
        while (temp != null) {
            if (!visited[temp.data]) {
                stack.Push(temp.data);
                visited[temp.data] = true;
                vertices_reached++;
            }
            temp = temp.nextElement;
        }
    } //end of while
    visited = null;
    return vertices_reached + 1; //+1 to include the source itself.
}
        static int findMotherVertex(Graph g)
        {
            
    //Traverse the Graph Array and perform DFS operation on each vertex
    //The vertex whose DFS Traversal results is equal to the total number
    //of vertices in graph is a mother vertex
    int num_of_vertices_reached = 0;
    for (int i = 0; i < g.getVertices(); i++) {
        num_of_vertices_reached = performDFS(g, i);
        if (num_of_vertices_reached == g.getVertices()){
            return i;
        }   
    }
    return - 1;
        }
        static void Main(string[] args)
        {
            Graph g = new Graph(4);
            g.addEdge(0, 1);
            g.addEdge(1, 2);
            g.addEdge(3, 0);
            g.addEdge(3, 1);
            Console.WriteLine(findMotherVertex(g));
        }
    }
}