题目描述 Farmer John and his cows are planning to leave town for a long vacation, and so FJ wants to temporarily close down his farm to save money in the meantime. The farm consists of NN barns connected with MM bidirectional paths between some pairs of…

传送门 题目大意: n个谷仓 ,每次关闭一个谷仓,问剩下没被关闭的谷仓是 否联通. 题解:并查集+倒序处理 代码: #include<iostream> #include<cstdio> #include<cstring> #define N 3030 using namespace std; int n,m,sumedge,cnt; int head[N],fa[N],q[N],ans[N],exit[N]; struct Edge{ int x,y,nxt; Edg…

农夫约翰和他的奶牛准备去旅行,所以约翰想要把他的农场临时关闭. 农场有N个牛棚(牛棚从1到N编号),有M条路连接这些牛棚(1≤N,M≤3000). 约翰打算挨个关闭牛棚,在关牛棚的时候, 他突然想起一个有趣的问题:剩余的这些没有关闭的牛棚是不是连通呢? 连通指的是从任何一个牛棚出发,都能到达其他牛棚(注意:已经关闭的牛棚不可以通行). Input 第一行包括两个整数N M, 接下来M行,每行输入两个整数x y,表示x和y牛棚之间存在一条路,路是双向通行的. 接下来n行,表示关牛棚的顺序. Out…

题目描述 FJ和他的奶牛们正在计划离开小镇做一次长的旅行,同时FJ想临时地关掉他的农场以节省一些金钱. 这个农场一共有被用M条双向道路连接的N个谷仓(1<=N,M<=3000).为了关闭整个农场,FJ 计划每一次关闭掉一个谷仓.当一个谷仓被关闭了,所有的连接到这个谷仓的道路都会被关闭,而且再也不能够被使用. FJ现在正感兴趣于知道在每一个时间(这里的“时间”指在每一次关闭谷仓之后的时间)时他的农场是否是“全连通的”——也就是说从任意的一个开着的谷仓开始,能够到达另外的一个谷仓.注意自从某一个时…

题目描述 Farmer John and his cows are planning to leave town for a long vacation, and so FJ wants to temporarily close down his farm to save money in the meantime. The farm consists of  barns connected with  bidirectional paths between some pairs of barn…

https://www.luogu.org/problem/P3144 每次关闭一个农场,农场之间有边相连,问每次关闭后开着的农场是否是一个连通块: 数据小,离线搞: 我们先记录删的顺序,然后倒着来,先将所有删去的点都标记,每次加点,再把所有没删的都加在一起, in_class[i]==1表示这个点在农场里: 我们从一个删点的过程变成一个加点的过程: 因为在第n次点都删完了,所以一定是一个连通块(体积为0): #include<cstdio> #include<cstring> #…

题目描述 in English: Farmer John and his cows are planning to leave town for a long vacation, and so FJ wants to temporarily close down his farm to save money in the meantime. The farm consists of NN barns connected with MM bidirectional paths between so…

题目描述 每年,在威斯康星州,奶牛们都会穿上衣服,收集农夫约翰在N(1<=N<=100,000)个牛棚隔间中留下的糖果,以此来庆祝美国秋天的万圣节. 由于牛棚不太大,FJ通过指定奶牛必须遵循的穿越路线来确保奶牛的乐趣.为了实现这个让奶牛在牛棚里来回穿梭的方案,FJ在第i号隔间上张贴了一个“下一个隔间”Next_i(1<=Next_i<=N),告诉奶牛要去的下一个隔间:这样,为了收集它们的糖果,奶牛就会在牛棚里来回穿梭了. FJ命令奶牛i应该从i号隔间开始收集糖果.如果一只奶牛回到某…

P3143 [USACO16OPEN]钻石收藏家Diamond Collector 题目描述 Bessie the cow, always a fan of shiny objects, has taken up a hobby of mining diamonds in her spare time! She has collected \(N\) diamonds (\(N \leq 50,000\) of varying sizes, and she wants to arrange so…

P3143 [USACO16OPEN]钻石收藏家Diamond Collector 题目描述 Bessie the cow, always a fan of shiny objects, has taken up a hobby of mining diamonds in her spare time! She has collected NN diamonds (N \leq 50,000N≤50,000) of varying sizes, and she wants to arrange…