Luogu2860 [USACO06JAN]冗余路径Redundant Paths 给定一个连通无向图,求至少加多少条边才能使得原图变为边双连通分量 \(1\leq n\leq5000,\ n-1\leq m\leq10^4\) tarjan 边双无疑不用考虑,于是就可以边双缩点成一棵树 令现在要连的边为 \((u,\ v)\) ,当前树上 \(bl_u\) 到 \(bl_v\) 的链将会变为一个新的点双,可以将他们看为一个新的点 可以贪心地连边使得每次连边后,不复存在的点尽量多,当只剩一个点时…

P2860 [USACO06JAN]冗余路径Redundant Paths 题目描述 为了从F(1≤F≤5000)个草场中的一个走到另一个,贝茜和她的同伴们有时不得不路过一些她们讨厌的可怕的树．奶牛们已经厌倦了被迫走某一条路,所以她们想建一些新路,使每一对草场之间都会至少有两条相互分离的路径,这样她们就有多一些选择． 每对草场之间已经有至少一条路径．给出所有R(F-1≤R≤10000)条双向路的描述,每条路连接了两个不同的草场,请计算最少的新建道路的数量, 路径由若干道路首尾相连而成．两条路径相…

P2860 [USACO06JAN]冗余路径Redundant Paths 为了从F(1≤F≤5000)个草场中的一个走到另一个,贝茜和她的同伴们有时不得不路过一些她们讨厌的可怕的树．奶牛们已经厌倦了被迫走某一条路,所以她们想建一些新路,使每一对草场之间都会至少有两条相互分离的路径,这样她们就有多一些选择． 每对草场之间已经有至少一条路径．给出所有R(F-1≤R≤10000)条双向路的描述,每条路连接了两个不同的草场,请计算最少的新建道路的数量, 路径由若干道路首尾相连而成．两条路径相互分离,是…

题目描述 In order to get from one of the F (1 <= F <= 5,000) grazing fields (which are numbered 1..F) to another field, Bessie and the rest of the herd are forced to cross near the Tree of Rotten Apples. The cows are now tired of often being forced to t…

题目描述 In order to get from one of the F (1 <= F <= 5,000) grazing fields (which are numbered 1-F) to another field, Bessie and the rest of the herd are forced to cross near the Tree of Rotten Apples. The cows are now tired of often being forced to ta…

题目描述 In order to get from one of the F (1 <= F <= 5,000) grazing fields (which are numbered 1..F) to another field, Bessie and the rest of the herd are forced to cross near the Tree of Rotten Apples. The cows are now tired of often being forced to t…

题目描述 In order to get from one of the F (1 <= F <= 5,000) grazing fields (which are numbered 1..F) to another field, Bessie and the rest of the herd are forced to cross near the Tree of Rotten Apples. The cows are now tired of often being forced to t…

题目描述 In order to get from one of the F (1 <= F <= 5,000) grazing fields (which are numbered 1..F) to another field, Bessie and the rest of the herd are forced to cross near the Tree of Rotten Apples. The cows are now tired of often being forced to t…

题目链接:https://www.luogu.org/problemnew/show/P2860 考虑在无向图上缩点. 运用到边双.桥的知识. 缩点后统计度为1的点. 度为1是有一条路径,度为2是有两条路径. #include <stack> #include <cstdio> #include <cstring> #include <iostream> #include <algorithm> using namespace std; cons…

(写题解不容易,来我的博客玩玩咯qwq~) 该题考察的知识点是边双连通分量 边双连通分量即一个无向图中,去掉一条边后仍互相连通的极大子图.(单独的一个点也可能是一个边双连通分量) 换言之,一个边双连通分量中不包含桥. 例如下图(样例)中的边双连通分量有(1),(2,3,5,6),(4),(7) 不难发现,在一个边双连通分量中,任意两点都存在至少两条互相分离的路径:(如1->2与1->3->2) 如若不在一个边双连通分量中,则可能经过桥(甚至不联通)如:2->4. 由于桥是必须通过的…