from nose.tools import *
from networkx.utils import reverse_cuthill_mckee_ordering
import networkx as nx

def test_reverse_cuthill_mckee():
    # example graph from 
    # http://www.boost.org/doc/libs/1_37_0/libs/graph/example/cuthill_mckee_ordering.cpp
    G = nx.Graph([(0,3),(0,5),(1,2),(1,4),(1,6),(1,9),(2,3),
                  (2,4),(3,5),(3,8),(4,6),(5,6),(5,7),(6,7)])
    rcm = list(reverse_cuthill_mckee_ordering(G,start=0))    
    assert_equal(rcm,[9, 1, 4, 6, 7, 2, 8, 5, 3, 0])
    rcm = list(reverse_cuthill_mckee_ordering(G))    
    assert_equal(rcm,[0, 8, 5, 7, 3, 6, 4, 2, 1, 9])