From 3cae7967acf2cdef9c65b39547ccec2115c16410 Mon Sep 17 00:00:00 2001 From: bT-53 Date: Fri, 27 Oct 2017 10:10:29 +0700 Subject: [PATCH] Create scc_kosaraju.py --- Graphs/scc_kosaraju.py | 45 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 Graphs/scc_kosaraju.py diff --git a/Graphs/scc_kosaraju.py b/Graphs/scc_kosaraju.py new file mode 100644 index 000000000..09a05e981 --- /dev/null +++ b/Graphs/scc_kosaraju.py @@ -0,0 +1,45 @@ +# n - no of nodes, m - no of edges +n, m = list(map(int,input().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().split())) + g[u].append(v) + r[v].append(u) + +stack = [] +visit = [False]*n +scc = [] +component = [] + +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 + +print(kosaraju())