class Graph:
def init(self):
self.dic = {}
self.vis = [0] * 100001
self.timer = 1
self.tin = [0] * 100001
self.low = [0] * 100001
self.ap = set()
def add_edge(self, a, b):
if a in self.dic:
self.dic[a].append(b)
else:
self.dic[a] = [b]
if b in self.dic:
self.dic[b].append(a)
else:
self.dic[b] = [a]
def dfs(self, node, par):
self.vis[node] = 1
self.low[node] = self.timer
self.tin[node] = self.timer
self.timer += 1
cc = 0
for child in self.dic[node]:
if child == par:
continue
elif self.vis[child] == 1:
self.low[node] = min(self.low[node], self.tin[child])
else:
self.dfs(child, node)
cc += 1
self.low[node] = min(self.low[node], self.low[child])
if self.tin[node] <= self.low[child] and par != -1:
self.ap.add(node)
# print(node)
# print(self.low[:10])
if par == -1 and cc > 1:
self.ap.add(node)
# print(node)
while True:
g = Graph()
n = 0
m = 0
try:
n, m = map(int, input().split())
except:
pass
if n == 0 and m == 0:
break
for i in range(m):
a = 0
b = 0
a, b = map(int, input().split())
g.add_edge(a, b)
for i in range(1, n + 1):
if g.vis[i] != 1:
g.dfs(i, -1)
print(len(g.ap))
I am getting Runtime error(NZEC). Can anyone help?
