public class Warshall
{

   public static void print(int[][] G)
   {
      int i, j;

      for (i=0; i < G.length; i++)
      {
         for (j=0; j < G.length; j++)
	    if ( G[i][j] != 0 )
	       System.out.println(i + " --> " + j);
      }
      System.out.println();
   }

   public static void main(String[] args)
   {
//                        0  1  2  3  
// ===================================================
      int[][] G =    {  { 0, 1, 0, 0 },  // 0
			{ 0, 0, 1, 0 },  // 1
			{ 0, 0, 0, 1 },  // 2
			{ 0, 0, 0, 0 } };// 3

      int i, j, k;


      System.out.println("Initial relation:");
      print(G);

      for ( k = 0; k < G.length; k++ )
      {
         for ( i = 0; i < G.length; i++ )
         {
             for ( j = 0; j < G.length; j++ )
   	     {
   	        if ( G[i][k] != 0 && G[k][j] != 0 )
   	        {
   	           G[i][j] = 1;
   	        }
             }
          }
       }


      System.out.println("Transitive closure:");
      print(G);

   }
}