Find Cycle In A Graph

/*Copyrights to vsdevelopers.io*/
/*For more programs visit vsdevelopers.io */
/*Java program to find whether a cycle exists in given graph*/
import java.util.Iterator;
import java.util.LinkedList;

public class VSDGraphCycle {
	public static class VSDGraph {
		int v;
		LinkedList<Integer> adList[];

		VSDGraph(int size) {
			v = size;// No.of vertices
			adList = new LinkedList[v];// Adjacency list to mark the edges
			// Initializing vertices using constructor
			for (int i = 0; i < v; i++)
				adList[i] = new LinkedList<Integer>();
		}

		// Function to add edge to the graph
		void VSDaddEdge(int v1, int v2) {
			adList[v1].add(v2);
		}

		// Function to detect the cycle using BFS
		boolean VSDCycle(int s) {
			boolean visited[] = new boolean[v];// Array to mark visited vertices
			LinkedList<Integer> Queue = new LinkedList<Integer>();// Queue to traverse over vertices breadth wise
			visited[s] = true;
			Queue.add(s);
			while (Queue.size() != 0) {
				s = (int) Queue.poll();
				Iterator i = adList[s].iterator();
				while (i.hasNext()) {
					int temp = (int) i.next();
					if (visited[temp] == true)
						return true;
					else {
						visited[temp] = true;
						Queue.add(temp);
					}

				}
			}

			return false;
		}
	}

	public static void main(String args[]) {
		VSDGraph g = new VSDGraph(8);
		g.VSDaddEdge(0, 7);
		g.VSDaddEdge(0, 2);
		g.VSDaddEdge(1, 3);
		g.VSDaddEdge(1, 7);
		g.VSDaddEdge(2, 4);
		g.VSDaddEdge(2, 6);
		g.VSDaddEdge(3, 5);

		boolean b = g.VSDCycle(0);
		if (b)
			System.out.println("Cycle exists");
		else
			System.out.println("Cycle does not exist");

	}

}