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34 lines
769 B
Python
34 lines
769 B
Python
# Kahn's Algorithm is used to find Topological ordering of Directed Acyclic Graph using BFS
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def topologicalSort(l):
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indegree = [0] * len(l)
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queue = []
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topo = []
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cnt = 0
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for key, values in l.items():
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for i in values:
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indegree[i] += 1
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for i in range(len(indegree)):
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if indegree[i] == 0:
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queue.append(i)
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while queue:
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vertex = queue.pop(0)
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cnt += 1
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topo.append(vertex)
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for x in l[vertex]:
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indegree[x] -= 1
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if indegree[x] == 0:
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queue.append(x)
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if cnt != len(l):
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print("Cycle exists")
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else:
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print(topo)
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# Adjacency List of Graph
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l = {0: [1, 2], 1: [3], 2: [3], 3: [4, 5], 4: [], 5: []}
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topologicalSort(l)
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