mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-12-18 01:00:15 +00:00
c909da9b08
* 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
|
|
|
|
|
|
# A Bipartite Graph is a graph whose vertices can be divided into two independent sets,
|
|
# U and V such that every edge (u, v) either connects a vertex from U to V or a vertex
|
|
# from V to U. In other words, for every edge (u, v), either u belongs to U and v to V,
|
|
# or u belongs to V and v to U. We can also say that there is no edge that connects
|
|
# vertices of same set.
|
|
from queue import Queue
|
|
|
|
|
|
def check_bipartite(graph):
|
|
queue = Queue()
|
|
visited = [False] * len(graph)
|
|
color = [-1] * len(graph)
|
|
|
|
def bfs():
|
|
while not queue.empty():
|
|
u = queue.get()
|
|
visited[u] = True
|
|
|
|
for neighbour in graph[u]:
|
|
if neighbour == u:
|
|
return False
|
|
|
|
if color[neighbour] == -1:
|
|
color[neighbour] = 1 - color[u]
|
|
queue.put(neighbour)
|
|
|
|
elif color[neighbour] == color[u]:
|
|
return False
|
|
|
|
return True
|
|
|
|
for i in range(len(graph)):
|
|
if not visited[i]:
|
|
queue.put(i)
|
|
color[i] = 0
|
|
if bfs() is False:
|
|
return False
|
|
|
|
return True
|
|
|
|
|
|
if __name__ == "__main__":
|
|
# Adjacency List of graph
|
|
print(check_bipartite({0: [1, 3], 1: [0, 2], 2: [1, 3], 3: [0, 2]}))
|