/*

* Sample usage: java TransitiveClosure tinyDG.txt

* Sample usage: java TransitiveClosure mediumDG.txt

*/

public class TransitiveClosure {

private DirectedDFS[] all;

public TransitiveClosure(Digraph G){

all = new DirectedDFS[G.V()];

for (int v=0; v<G.V(); v++)

all[v] = new DirectedDFS(G, v);

}

public boolean reachable(int v, int w){

return all[v].marked(w);

}

public static void main(String[] args){

In in = new In(args[0]);

Digraph G = new Digraph(in);

TransitiveClosure tc = new TransitiveClosure(G);

StdOut.print(" ");

for (int v = 0; v < G.V(); v++)

StdOut.printf("%3d", v);

StdOut.println();

StdOut.println("--------------------------------------------");

// print transitive closure

for (int v = 0; v < G.V(); v++) {

StdOut.printf("%3d: ", v);

for (int w = 0; w < G.V(); w++) {

if (tc.reachable(v, w)) StdOut.print(" T");

else StdOut.print(" ");

}

StdOut.println();

}

}

}