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1f8a21d727
* Tighten up psf/black and flake8
* Fix some tests
* Fix some E741
* Fix some E741
* updating DIRECTORY.md
Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
56 lines
1.3 KiB
Python
56 lines
1.3 KiB
Python
# Finding Articulation Points in Undirected Graph
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def computeAP(l): # noqa: E741
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n = len(l)
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outEdgeCount = 0
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low = [0] * n
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visited = [False] * n
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isArt = [False] * n
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def dfs(root, at, parent, outEdgeCount):
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if parent == root:
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outEdgeCount += 1
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visited[at] = True
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low[at] = at
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for to in l[at]:
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if to == parent:
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pass
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elif not visited[to]:
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outEdgeCount = dfs(root, to, at, outEdgeCount)
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low[at] = min(low[at], low[to])
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# AP found via bridge
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if at < low[to]:
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isArt[at] = True
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# AP found via cycle
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if at == low[to]:
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isArt[at] = True
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else:
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low[at] = min(low[at], to)
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return outEdgeCount
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for i in range(n):
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if not visited[i]:
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outEdgeCount = 0
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outEdgeCount = dfs(i, i, -1, outEdgeCount)
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isArt[i] = outEdgeCount > 1
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for x in range(len(isArt)):
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if isArt[x] is True:
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print(x)
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# Adjacency list of graph
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data = {
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0: [1, 2],
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1: [0, 2],
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2: [0, 1, 3, 5],
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3: [2, 4],
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4: [3],
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5: [2, 6, 8],
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6: [5, 7],
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7: [6, 8],
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8: [5, 7],
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}
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computeAP(data)
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