mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-12-18 17:20:16 +00:00
33 lines
761 B
Python
33 lines
761 B
Python
# Kahn's Algorithm is used to find Topological ordering of Directed Acyclic Graph using BFS
|
|
def topologicalSort(l):
|
|
indegree = [0] * len(l)
|
|
queue = []
|
|
topo = []
|
|
cnt = 0
|
|
|
|
for key, values in l.items():
|
|
for i in values:
|
|
indegree[i] += 1
|
|
|
|
for i in range(len(indegree)):
|
|
if indegree[i] == 0:
|
|
queue.append(i)
|
|
|
|
while(queue):
|
|
vertex = queue.pop(0)
|
|
cnt += 1
|
|
topo.append(vertex)
|
|
for x in l[vertex]:
|
|
indegree[x] -= 1
|
|
if indegree[x] == 0:
|
|
queue.append(x)
|
|
|
|
if cnt != len(l):
|
|
print("Cycle exists")
|
|
else:
|
|
print(topo)
|
|
|
|
# Adjacency List of Graph
|
|
l = {0:[1,2], 1:[3], 2:[3], 3:[4,5], 4:[], 5:[]}
|
|
topologicalSort(l)
|