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https://github.com/TheAlgorithms/Python.git
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Christian Clauss
0525ef5da8
* ruff rule ANN202 missing-return-type-private-function * ruff rule ANN202 missing-return-type-private-function
55 lines
1.3 KiB
Python
55 lines
1.3 KiB
Python
from __future__ import annotations
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def dfs(u) -> None:
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global graph, reversed_graph, scc, component, visit, stack
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if visit[u]:
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return
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visit[u] = True
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for v in graph[u]:
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dfs(v)
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stack.append(u)
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def dfs2(u) -> None:
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global graph, reversed_graph, scc, component, visit, stack
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if visit[u]:
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return
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visit[u] = True
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component.append(u)
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for v in reversed_graph[u]:
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dfs2(v)
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def kosaraju():
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global graph, reversed_graph, scc, component, visit, stack
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for i in range(n):
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dfs(i)
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visit = [False] * n
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for i in stack[::-1]:
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if visit[i]:
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continue
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component = []
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dfs2(i)
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scc.append(component)
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return scc
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if __name__ == "__main__":
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# n - no of nodes, m - no of edges
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n, m = list(map(int, input().strip().split()))
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graph: list[list[int]] = [[] for _ in range(n)] # graph
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reversed_graph: list[list[int]] = [[] for i in range(n)] # reversed graph
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# input graph data (edges)
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for _ in range(m):
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u, v = list(map(int, input().strip().split()))
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graph[u].append(v)
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reversed_graph[v].append(u)
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stack: list[int] = []
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visit: list[bool] = [False] * n
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scc: list[int] = []
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component: list[int] = []
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print(kosaraju())
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