Exemplo n.º 1
0
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
Exemplo n.º 2
0
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
Exemplo n.º 4
0
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]
Exemplo n.º 5
0
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 ]