mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-10-06 13:49:30 +00:00
52 lines
1.0 KiB
Python
52 lines
1.0 KiB
Python
def dfs(u):
|
|
global g, r, scc, component, visit, stack
|
|
if visit[u]:
|
|
return
|
|
visit[u] = True
|
|
for v in g[u]:
|
|
dfs(v)
|
|
stack.append(u)
|
|
|
|
|
|
def dfs2(u):
|
|
global g, r, scc, component, visit, stack
|
|
if visit[u]:
|
|
return
|
|
visit[u] = True
|
|
component.append(u)
|
|
for v in r[u]:
|
|
dfs2(v)
|
|
|
|
|
|
def kosaraju():
|
|
global g, r, scc, component, visit, stack
|
|
for i in range(n):
|
|
dfs(i)
|
|
visit = [False] * n
|
|
for i in stack[::-1]:
|
|
if visit[i]:
|
|
continue
|
|
component = []
|
|
dfs2(i)
|
|
scc.append(component)
|
|
return scc
|
|
|
|
|
|
if __name__ == "__main__":
|
|
# n - no of nodes, m - no of edges
|
|
n, m = list(map(int, input().strip().split()))
|
|
|
|
g = [[] for i in range(n)] # graph
|
|
r = [[] for i in range(n)] # reversed graph
|
|
# input graph data (edges)
|
|
for i in range(m):
|
|
u, v = list(map(int, input().strip().split()))
|
|
g[u].append(v)
|
|
r[v].append(u)
|
|
|
|
stack = []
|
|
visit = [False] * n
|
|
scc = []
|
|
component = []
|
|
print(kosaraju())
|