第五周作业——有向图邻接表表示及反向图构造

1. 有向图中反向图构造。对tinyDG.txt（http://pan.baidu.com/s/1o6jWtcA）文件所表示的图，输出其邻接表表示 与 反向图的邻接表表示。类名：GraphReverse。

邻接表表示示例如下：

0:1 5

1:

2:0 3

……

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package alsys5_1;import java.io.*;import java.util.*;public class GraphReverse {private int vertex;//有向图顶点private int edge;//有向图边private boolean visited[];private List<ArrayList<Integer>> graphListS;//有向图private List<ArrayList<Integer>> graphListF;//有向图的反向图//构造函数public GraphReverse(int vertex,int edge,List<ArrayList<Integer>> graphListS,List<ArrayList<Integer>> graphListF){this.vertex=vertex;visited=new boolean[vertex];this.graphListS=graphListS;this.graphListF=graphListF;}//广度优先遍历生成邻接表private void BFS(int v,List<ArrayList<Integer>> graphList){Queue<Integer> que=new LinkedList<Integer>();//导入数组队列que.offer(v);//插入顶点while(!que.isEmpty()){v=que.poll();//检索队列System.out.print(v+":");//邻接表visited[v]=true;for(int i=0;i<graphList.get(v).size();i++){int k=graphList.get(v).get(i);System.out.print(k+" ");if(!visited[k]){que.offer(k);visited[k]=true;}}System.out.println();}}public static void main(String[] args){String path="e:/tinyDG.txt";try{Scanner scanner=new Scanner(new File(path));List<ArrayList<Integer>> graphListS=new ArrayList<ArrayList<Integer>>();//有向图的存储List<ArrayList<Integer>> graphListF=new ArrayList<ArrayList<Integer>>();//有向图的反向图的存储int vertex=scanner.nextInt();int edge=scanner.nextInt();//有向图构造for(int i=0;i<vertex;i++){graphListS.add(new ArrayList<Integer>());graphListF.add(new ArrayList<Integer>());}//有向图的反向图构造for(int i=0;i<edge;i++){int u=scanner.nextInt();int v=scanner.nextInt();if(!graphListS.get(u).contains(v)){graphListS.get(u).add(v);}if(!graphListF.get(v).contains(u)){graphListF.get(v).add(u);}}GraphReverse g1=new GraphReverse(vertex,edge,graphListS,null);System.out.println("有向图的邻接表的结果是： ");g1.BFS(vertex/2+1,graphListS);GraphReverse g2=new GraphReverse(vertex,edge,null,graphListF);System.out.println("有向图的反向图的邻接表结果是 ：  ");g2.BFS(1,graphListF);}catch(Exception e){e.printStackTrace();}}}

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