Connections between cities Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 4057    Accepted Submission(s): 1178 Problem Description After World War X, a lot of cities have been seriously damage…

看了标答感觉思路清晰了许多,用并查集来维护全联通块的点数和边权和. 用另一个up[]数组(也是并查集)来保证每条边不会被重复附权值,这样我们只要将询问按权值从小到大排序,一定能的到最小的边权和与联通块中的点数. 下面是过程分析.过程中一共运用了两个并查集. [数据]110 31 21 32 42 53 63 74 85 95 109 6 3 1 501 4 2 5 209 10 8 10 40[分析]首先我们将图构建出来我们将m次询问按权值从小到大排序后: 1 4 2 5 209 10 8 10…

Network Time Limit: 5000MS   Memory Limit: 65536K Total Submissions: 13172   Accepted: 4774 题目链接:http://poj.org/problem?id=3694 Description: A network administrator manages a large network. The network consists of N computers and M links between pair…

Description 给定$N$个点和 $M$条边的无向联通图, 有$Q$ 次操作, 连接两个点的边, 问每次操作后的图中有几个桥 Solution 首先Tarjan找出边双联通分量, 每个双联通分量缩成一个点, 就构成了一棵树, 每一条树边都是桥. 执行连$u, v$ 边时, 用并查集跳到没有桥的深度最浅并且深度比$lca$深的点, 将它与父节点的并查集合并, 再接着跳. 每跳一次, 桥的数量就减少$1$. 另外感谢Iowa 神犇提醒我$cut$数组要开$M << 1$, 不是 $N &l…

题意: 就是有几个点,你掌控了几条路,你的商业对手也掌控了几条路,然后你想让游客都把你的所有路都走完,那么你就有钱了,但你又想挣的钱最多,真是的过分..哈哈 游客肯定要对比一下你的对手的路 看看那个便宜 就走哪个,(你的路的价钱和对手相等时 优先走你的): 思路想到了 但写不出来...真的有点巧妙了 用并查集来记录环路  如果两个点不能加入到并查集,那么肯定是加入这两个点后就构成了一个环路  记录下构成环路的u和v两点 其它点加入并查集 并加入到邻接表 dfs走一遍 记录下每个点的父结点 和 每…

题意:给你一个无向图,有q次操作,每次连接两个点,问你每次操作后有几个桥 思路:我们先用tarjan求出所有的桥,同时我们可以用并查集缩点,fa表示缩点后的编号,还要记录每个节点父节点pre.我们知道,缩点后形成一棵树,所有边都是桥,连接两点必会成环,环上任意边都不是桥.所以连点后,我们把两个点一步一步往上走,如果往上走之后发现fa不一样,说明走过了一条桥,那么合并fa,桥数量-1. 代码: #include<set> #include<map> #include<stack…

Network Time Limit: 5000MS   Memory Limit: 65536K       Description A network administrator manages a large network. The network consists of N computers and M links between pairs of computers. Any pair of computers are connected directly or indirectl…

Phone Call Time Limit: 6000/3000 MS (Java/Others)    Memory Limit: 524288/524288 K (Java/Others)Total Submission(s): 156    Accepted Submission(s): 67 Problem Description There are n houses in Bytetown, labeled by 1,2,...,n. In each house, there is a…

传送门  Wireless Network Time Limit: 10000MS   Memory Limit: 65536K Total Submissions: 24513   Accepted: 10227 Description An earthquake takes place in Southeast Asia. The ACM (Asia Cooperated Medical team) have set up a wireless network with the lap co…

Wireless Network Time Limit: 10000MS   Memory Limit: 65536K Total Submissions: 16065   Accepted: 6778 Description An earthquake takes place in Southeast Asia. The ACM (Asia Cooperated Medical team) have set up a wireless network with the lap computer…