在线判断显示运行时错误

Question

我的代码适用于所有测试用例。然而，当我将它提交给SPOJ时，它会显示NZEC运行时错误。

http://www.spoj.com/problems/BUGLIFE/

def dfs(graph, start, visited = None, parent = None):
    if visited == None:
        visited = set()
        visited.add(start)
    for num in graph[start]:
        if num not in visited:
            visited.add(num)
            if dfs(graph,num,visited,start):
                return True
        else:
            if num != parent:
                return True
    return False
tc = int(raw_input())
for i in range(1, tc+1):
    yo = {}
    s = raw_input()
    n, r = map(int, s.split())
    for j in range(r):
        s = raw_input()
        p, q = map(int, s.split())
        yo[p] = yo.get(p,[]) + [q]
        yo[q] = yo.get(q,[]) + [p]
    start = q
    if dfs(yo, start):
        print "Scenario #%d:" %(i)
        print "Suspicious bugs found!"
    else:
        print "Scenario #%d:" %(i)
        print "No suspicious bugs found!"

Answer 1

可能是由stackoverflow引起的。因为测试用例可能有2000个节点。

请参阅此Link