def main():
G = get_random_graph()
from graph_bfs import BFS
print "Test graph BFS", BFS, '-'*20
print 'Start with node id=5 =>', BFS(G, 5)
from graph_dfs import DFS
print "Test graph DFS", DFS, '-'*20
print 'Start with node id=5 =>', DFS(G)
from graph_toposort import topological_sort
print "Test topological sort", topological_sort, '-'*20
print 'Sorted list =>', topological_sort(G)
from graph_strongly_connected_component import SCC
print "Test SCC", SCC, '-'*20
print 'SCC => done', SCC(G)
from graph_mst_prim import MST_PRIM
print "Test graph MST Prim", MST_PRIM, '-'*20
print 'Start with node 5 =>', MST_PRIM(G, 5)
from graph_mst_kruskal import MST_KRUSKAL
print "Test graph MST Kruskal", MST_KRUSKAL, '-'*20
print 'MST =>', len(G.edges()), len(MST_KRUSKAL(G))
pass
def SCC(G):
G = DFS(G)
L = [(u[0], u[1]['f']) for u in G.nodes(data=True)]
L.sort(key=lambda x: -x[1])
L = [x[0] for x in L]
H = transpose(G)
# DFS the G^T in decreasing finish time
for n in H.nodes(data=True):
n[1]['c'] = 0
n[1]['d'] = float('inf')
n[1]['f'] = 0
n[1]['p'] = None
time = 0
for n in L:
if H.node[n]['c'] == 0:
DFS_VISIT(H, n)
return H
def SCC(G):
G = DFS(G)
L = [ (u[0],u[1]['f']) for u in G.nodes(data=True) ]
L.sort(key=lambda x: -x[1])
L = [ x[0] for x in L ]
H = transpose(G)
# DFS the G^T in decreasing finish time
for n in H.nodes(data=True):
n[1]['c'] = 0
n[1]['d'] = float('inf')
n[1]['f'] = 0
n[1]['p'] = None
time = 0
for n in L:
if H.node[n]['c'] == 0:
DFS_VISIT(H, n)
return H
def topological_sort(G):
G = DFS(G)
L = [(u[0], u[1]['f']) for u in G.nodes(data=True)]
L.sort(key=lambda x: -x[1])
return [x[0] for x in L]
def topological_sort(G):
G = DFS(G)
L = [ (u[0],u[1]['f']) for u in G.nodes(data=True) ]
L.sort(key=lambda x: -x[1])
return [ x[0] for x in L ]
