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* pre-commit: Upgrade psf/black for stable style 2023 Updating https://github.com/psf/black ... updating 22.12.0 -> 23.1.0 for their `2023 stable style`. * https://github.com/psf/black/blob/main/CHANGES.md#2310 > This is the first [psf/black] release of 2023, and following our stability policy, it comes with a number of improvements to our stable style… Also, add https://github.com/tox-dev/pyproject-fmt and https://github.com/abravalheri/validate-pyproject to pre-commit. I only modified `.pre-commit-config.yaml` and all other files were modified by pre-commit.ci and psf/black. * [pre-commit.ci] auto fixes from pre-commit.com hooks for more information, see https://pre-commit.ci --------- Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
48 lines
1.3 KiB
Python
48 lines
1.3 KiB
Python
# Check whether Graph is Bipartite or Not using BFS
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# A Bipartite Graph is a graph whose vertices can be divided into two independent sets,
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# U and V such that every edge (u, v) either connects a vertex from U to V or a vertex
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# from V to U. In other words, for every edge (u, v), either u belongs to U and v to V,
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# or u belongs to V and v to U. We can also say that there is no edge that connects
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# vertices of same set.
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from queue import Queue
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def check_bipartite(graph):
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queue = Queue()
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visited = [False] * len(graph)
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color = [-1] * len(graph)
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def bfs():
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while not queue.empty():
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u = queue.get()
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visited[u] = True
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for neighbour in graph[u]:
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if neighbour == u:
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return False
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if color[neighbour] == -1:
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color[neighbour] = 1 - color[u]
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queue.put(neighbour)
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elif color[neighbour] == color[u]:
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return False
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return True
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for i in range(len(graph)):
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if not visited[i]:
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queue.put(i)
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color[i] = 0
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if bfs() is False:
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return False
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return True
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if __name__ == "__main__":
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# Adjacency List of graph
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print(check_bipartite({0: [1, 3], 1: [0, 2], 2: [1, 3], 3: [0, 2]}))
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