**fig9_5.txt**

/* 1*/	void
/* 2*/	Topsort( Graph G )
/* 3*/	{
/* 4*/	    Vertex V, W;

/* 5*/	    for( int Counter = 1; Counter <= Num_Vertex; Counter++ )
/* 6*/	    {
/* 7*/	        V = Find_New_Vertex_Of_Indegree_Zero( );
/* 8*/	        if( V == Not_A_Vertex )
/* 9*/	        {
/*10*/	            Error( "Graph has a cycle" );
/*11*/	            return;
/*12*/	        }
/*13*/	        Top_Num[ V ] = Counter;
/*14*/	        for Each W Adjacent To V
/*15*/	            Indegree[ W ]--;
/*16*/	    }
/*17*/	}