有向无环图的拓扑排序

package com.data.struct;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

import com.data.struct.GraphicDepthFirst.Node;


public class GraphicDepthFirstSort {
  private Node[] list;
  private int time=0;
  private List<Node> sortList=new ArrayList<Node>();
  public GraphicDepthFirstSort(int v,int e){
    list=new Node[v];
    for(int i=0;i<v;i++){
      Node node=new Node();
      node.id=i;
      list[i]=node;
    }
    for(int i=0;i<e;i++){
      int v1=new Random().nextInt(v);
      int v2=new Random().nextInt(v);
      if(v1==v2){
        continue;
      }
      while(true){
        Node node=list[v1];
        boolean already=false;
        while(node.next!=null){
          if(node.next.id==v2){
            already=true;
            break;
          }
          node=node.next;
        }
        if(already==true){
          break;
        }
        Node ex=new Node();
        ex.id=v2;
        node.next=ex;
        break;
      }
    }
  }
  
  public List<Node> getSort(){
    return sortList;
  }
  public void printSort(){
    System.out.println("sort===========");
    for(int i=0;i<sortList.size();i++){
      System.out.print(sortList.get(i).id+"  ");;
    }
    System.out.println();
  }
  
  public void depthFirstSearch(){
    for(int i=0;i<list.length;i++){
      if(list[i].color==Node.WHITE){
        dfsVisit(list[i]);
      }
    }
  }
  
  private void dfsVisit(Node node){
    time++;
    node.d=time;
    node.color=Node.GRAY;
    Node w=list[node.id];
    Node u=w;
    while(w.next!=null){
      if(list[w.next.id].color==Node.WHITE){
        list[w.next.id].color=Node.GRAY;
        list[w.next.id].parent=u;
        dfsVisit(list[w.next.id]);
      }
      w=w.next;
    }
    node.color=Node.BLACK;
    time++;
    node.f=time;
    sortList.add(0, node);
  }
  
  public void printDepth(Node v){
    Node s=list[0];
    if(v==s){
      System.out.print(s.id+"=>");
    }else if(v.parent==null){
      System.out.print(v.id+"=>");
    }else {
      printDepth(v.parent);
      System.out.print(v.id+"=>");
    }
  }
  
  public void print(){
    for(int i=0;i<list.length;i++){
      Node node=list[i];
      System.out.print(node.id+"=>");
      while(node.next!=null){
        System.out.print(node.next.id+"=>");
        node=node.next;
      }
      System.out.println();
    }
    
  }
  public void printAllDepth(){
    System.out.println("path");
    for(int i=0;i<list.length;i++){
      printDepth(list[i]);
      System.out.println();
    }
  }
  
  public static class Node{
    public static final int WHITE=1;
    public static final int BLACK=2;
    public static final int GRAY=3;
    private int id;
    private Node next;
    private int color=WHITE;
    private int d=Integer.MAX_VALUE;
    private Node parent;
    private int f;
  }
  public static void main(String[] args)throws Exception {
    GraphicDepthFirstSort g=new GraphicDepthFirstSort(5,30);
    g.print();
    g.depthFirstSearch();
    g.printAllDepth();
    g.printSort();
    
    
  }

}

上面构造的图，并不是有向无环图，但结果如果把它当作有向无环图，结果是正确的。