DFS

import java.io.File;
import java.util.Arrays;
import java.util.Scanner;

public class DFS {
    public static int node;
    public static int time;
    public static int[] color;
    public static int[] f;
    public static int[] d;
    public static int[] d1;
    public static int[] parent;
    public static int start;
    public static char[] nodes={'u','v','w','x','y','z'};

    public static int[] vertices=new int[] {0,1,2,3,4,5,6,7};
    public static int[][] matrix;
    //public static int node;


    public static void main(String [] args) {
     try{
            Scanner scn=new Scanner(new File("H:\\DFS Graph.txt"));
            String[] splitA;
            String temp=scn.nextLine();
            node=Integer.parseInt(temp);
         //   out.println(v);
           String temp2=scn.nextLine();
          int edge=Integer.parseInt(temp2);
            matrix=new int[node][node];
            while(scn.hasNext())
            {
            String line=scn.nextLine();
            splitA=line.split(",");
            int x=Integer.parseInt(splitA[0]);
            int y=Integer.parseInt(splitA[1]);
            matrix[x][y]=1;
            }

            //----------
             color=new int[node];
              d=new int[node];
           d1=new int[node];
               f=new int[node];
               parent=new int[node];
               start=0;
            //----------------------\\\

               //d[start]=0;
               //parent[start]=0;
               //3 1 6 7 5 4 2 0

            for(int i=0;i<node;i++) {
            color[i]=0;
            d[i]=0;
            f[i]=0;
            }



            time=0;
            //color[0]=1;

         //DFS_visit(3);
            for(int j=0;j<node;j++) {
            if(color[j]==0) {
                DFS_visit(j);
            }
            }
            print();
            printStart();


     }

            catch(Exception e) {
               e.printStackTrace();
              }
    }
    public static void DFS_visit(int u) {
        //System.out.print(u+"====>");
        color[u]=1;
        time++;
        d[u]=time;
        for(int c=0;c<node;c++) {
            if(matrix[u][c]==1) {
                if(color[c]==0) {

                    parent[c]=u;
                    DFS_visit(c);
                }
            }
        }
        color[u]=2;//black
        time=time+1;
        f[u]=time;
        System.out.print(nodes[u]+">");
    }
    public static void print() {
         System.out.println();
         System.out.println();
         for(int c=0;c<node;c++) {
             if(color[c]==2)
               System.out.print("Black"+",");
             else if(color[c]==1) {
                 System.out.print("Gray"+",");

             }
             else {
                 System.out.print("White"+",");
             }
       }
         System.out.println();
        System.out.println();
        System.out.println();
       }
    public static int findIndex(int arr[], int t)
    {

        // if array is Null
        if (arr == null) {
            return -1;
        }

        // find length of array
        int len = arr.length;
        int i = 0;

        // traverse in the array
        while (i < len) {

            // if the i-th element is t
            // then return the index
            if (arr[i] == t) {
                return i;
            }
            else {
                i = i + 1;
            }
        }
        return -1;
    }
    public static void printStart() {
        System.out.println("###-------START TIME---------###");
         System.out.println();

        for(int k=0;k<node;k++) {
            d1[k]=d[k];
            //System.out.println(d[k]);
            }


         Arrays.sort(d1);

          for(int j=0;j<node;j++) {

                    int b=(d1[j]);
                    //System.out.println(b);
                    int ind=findIndex(d,b);
                    System.out.print(nodes[ind]+"=>");
                }

    }
}