static int[] verticesInOrder(final int[] rank) {
        int[] vs = new int[rank.length];
        for (int v = 0; v < rank.length; v++)
            vs[rank[v]] = v;
        return vs;
    }
static int [ ] verticesInOrder ( final int [ ] rank ) { int [ ] vs = new int [ rank . length ] ; for ( int v = 0 ; v < rank . length ; v ++ ) vs [ rank [ v ] ] = v ; return vs ; }
Using the pre-computed rank, get the vertices in order.

@param rank see {@link #rank(int[][])}
@return vertices in order