public class Topological {
private Iterable<Integer> order;
public Topological(Digraph G) {
DirectedCycle cycleFinder = new DirectedCycle(G);
if(!cycleFinder.hasCycle()) {
DepthFirstOrder dfs = new DepthFirstOrder(G);
order = dfs.reversePost();
}
}
public Iterable<Integer> order() {
return order;
}
public boolean isDAG() {
return order() == null;
}
}
