将边集划分成若干极大不相交集合,满足每个简单环都可以由某些集合相加得到,则答案就是这些集合大小的$\gcd$的约数. 对于一个简单环,上面的边一定不是桥边,而和它在一个集合的边肯定不在其他简单环上.因此删除它之后,这些边就从非桥边变成了桥边. 枚举每条非桥边跑Tarjan计算答案即可. 时间复杂度$O(m(n+m))$. #include<cstdio> const int N=2005,BUF=21000; int n,m,i,x,y,now,ans,D,cut[N],g[N],v[N<…
Search GO 说明:输入题号直接进入相应题目,如需搜索含数字的题目,请在关键词前加单引号 Problem ID Title Source AC Submit Y 1000 A+B Problem 10983 18765 Y 1036 [ZJOI2008]树的统计Count 5293 13132 Y 1588 [HNOI2002]营业额统计 5056 13607 1001 [BeiJing2006]狼抓兔子 4526 18386 Y 2002 [Hnoi2010]Bounce 弹飞绵羊 43…
Travelling Tours Time limit: 1.0 secondMemory limit: 64 MB There are N cities numbered from 1 to N (1 ≤ N ≤ 200) and M two-way roads connect them. There are at most one road between two cities. In summer holiday, members of DSAP Group want to make so…
Cow Tours Farmer John has a number of pastures on his farm. Cow paths connect some pastures with certain other pastures, forming a field. But, at the present time, you can find at least two pastures that cannot be connected by any sequence of cow pat…
