Added Depth First Character Traversal for Graph as problem99

src/main/java/com/github/pedrovgs/problem99/Graph.java

@@ -0,0 +1,85 @@
+import java.io.*;
+import java.util.*; 
+class Graph
+{
+    private int V;
+    private int R;
+    private LinkedList<Integer> adj[];
+    ArrayList<Integer> trav;
+    Graph(int v,int rel)
+    {
+        V = v;
+        R = 2*rel;
+        adj = new LinkedList[v];
+        trav = new ArrayList<>();
+        for (int i=0; i<v; ++i)
+            adj[i] = new LinkedList<Integer>();
+    }
+    void addEdge(int l, int m)
+    {
+        adj[l].add(new Integer(m));
+        adj[m].add(new Integer(l));
+    }
+    void DFSUtil(int v,boolean visited[])
+    {
+        visited[v] = true;
+        //System.out.print(v+" ");
+        trav.add(new Integer(v));
+        Iterator<Integer> i = adj[v].listIterator();
+        while (i.hasNext())
+        {
+            int n = i.next();
+            if (!visited[n])
+                DFSUtil(n, visited);
+        }
+    }
+    ArrayList<Integer> DFS(int v)
+    {
+        boolean visited[] = new boolean[V];
+        DFSUtil(v, visited);
+
+        return trav;
+
+    }
+
+    public static void main(String args[])
+    {
+        Scanner sc = new Scanner(System.in);
+
+        System.out.println("Enter the number of vertices and relations: ");
+        int n = sc.nextInt();
+        int rel = sc.nextInt();
+
+        sc.nextLine();
+
+        System.out.println("Enter all the vertices: ");
+        String family = sc.nextLine();
+        char fam[] = new char[n];
+        char sorted_fam[] = new char[n];
+        for(int j = 0 ; j < n ; j++) {
+            fam[j] = family.charAt(2*j);
+            sorted_fam[j] = fam[j];
+        }
+
+        Graph g = new Graph(n,rel);
+
+        Arrays.sort(sorted_fam);
+
+        System.out.println("Enter the two vertices in "+rel+" relations (space separated) : ");
+
+        for(int j = 0 ; j <rel ; j++) {
+            String relation = sc.nextLine();
+            char src = relation.charAt(0);
+            char dest = relation.charAt(2);
+            g.addEdge(Arrays.binarySearch(sorted_fam, src),Arrays.binarySearch(sorted_fam, dest));
+        }
+        System.out.println("Enter the source vertex: ");
+        int source = Arrays.binarySearch(sorted_fam, sc.nextLine().charAt(0));
+        ArrayList<Integer> ans = g.DFS(source);
+
+        for(int j = 0 ; j < ans.size() ; j++) {
+        	System.out.print(sorted_fam[ans.get(j)] + " ");
+        }
+
+    }
+}