第五周作业——有向图邻接表表示及反向图构造

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;

public class GraphReverse {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		try {
			FileReader in = new FileReader("tinyDG.txt");
			BufferedReader br = new BufferedReader(in);
			int tempchar;
			String str = "";
			str = br.readLine();
			//System.out.println(str);
			int V = Integer.parseInt(str.trim());
			str = br.readLine();
			//System.out.println(str.trim());
			int E = Integer.parseInt(str);
			int[][] g = new int[V][V];
			str = "";
			int a = 0, b = 0;
			while ((tempchar = br.read()) != -1) {
				str = str + (char) tempchar;
				if ((char) tempchar == ' ') {
					if(!str.equals(""))
					a = Integer.parseInt(str.trim());
					str = "";
				}
				if ((char) tempchar == '\n') {
					b = Integer.parseInt(str.trim());
					g[a][b] = 1;
					//g[b][a] = 1;
					str = "";
				}
			}
			br.close();
			in.close();
			str = "";
			for (int i = 0; i < V; i++) {
				System.out.print("\n\r"+i+": ");
				for (int j = 0; j < V; j++) {
					if(g[i][j]==1){
						System.out.print(j+"   ");
					}
				}
			}
			System.out.println("\n\r\n\r反向图：");
			int[][] h=new int[V][V];
			for (int i = 0; i < V; i++) {
				for (int j = 0; j < V; j++) {
					if(g[i][j]==1){
						h[j][i]=1;
					}
				}
			}
			for (int i = 0; i < V; i++) {
				System.out.print("\n\r"+i+": ");
				for (int j = 0; j < V; j++) {
					if(h[i][j]==1){
						System.out.print(j+"   ");
					}
				}
			}
			
		} catch (NumberFormatException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}