/*有向图的DFS基本实现方法,-1表示不能走*/
package app;
import java.util.Scanner;
// import java.util.Queue;
class Tu2{
public static int maxn = 100;
static boolean []vis = new boolean[maxn];
static int[][] G = new int[maxn][maxn]; //存邻接矩阵
static int n; //有几个点
static char[] vhave = new char[maxn]; //存点
public static void main(String[] args)