def _kahn_adjacency_list(graph: Graph) -> list:
S = Queue()
in_degree = {u: 0 for u in graph.vertices}
for u in graph.vertices:
for v in graph.neighbors(u):
in_degree[v.name] += 1
for u in graph.vertices:
if in_degree[u] == 0:
S.append(u)
in_degree.pop(u)
L = []
while S:
n = S.popleft()
L.append(n)
for m in graph.neighbors(n):
graph.remove_edge(n, m.name)
in_degree[m.name] -= 1
if in_degree[m.name] == 0:
S.append(m.name)
in_degree.pop(m.name)
if in_degree:
raise ValueError("Graph is not acyclic.")
return L
def _job(graph: Graph, u: str):
for v in graph.neighbors(u):
graph.remove_edge(u, v.name)