Sabotage 题目链接:https://vjudge.net/problem/UVA-10480 Description: The regime of a small but wealthy dictatorship has been abruptly overthrown by an unexpected rebellion. Because of the enormous disturbances this is causing in world economy, an imperial…

题目链接:https://vjudge.net/problem/UVA-10480 题解: 实际就是求最小割集. 1.什么是网络流图的“割”?答:一个边的集合,使得网络流图删除这些边之后,点被分成两部分S和T, 且源点位于S中, 汇点位于T中.注意:不能存在独立于S和T的点. 2.对于最小割集中的边,它在残余网络中容量为0. 3.从源点出发,沿着有残余容量的边走,能够访问到的点都属于S集合,否则属于T集合. 代码如下: #include <iostream> #include <cstd…

题目链接:https://cn.vjudge.net/problem/UVA-10480 知识点: 最小割 题目大意: 求最小割并打印出最小割必须割掉的边. 解题思路: 在跑完 \(sap\) 后的残量网络上,记录源点和汇点可达的点,然后遍历所有的边(设边的两端点为 \(u\) 和 \(v\)),如果 \(u\) 源点可达而 \(v\) 汇点可达(或与之相反,\(v\) 源点可达而 \(u\) 汇点可达),则说明该边必须割. AC代码: #include <bits/stdc++.h> usi…

UVA 10480 Sabotage (网络流,最大流,最小割) Description The regime of a small but wealthy dictatorship has been abruptly overthrown by an unexpected rebel-lion. Because of the enormous disturbances this is causing in world economy, an imperialist military super…

1.破坏{DOLD题2} sabotage.pas/c/cpp [问题描述] 农夫约翰的头号敌人保罗决定破坏农民约翰的挤奶设备.挤奶设备排成一行,共N(3<= N <=100000)台挤奶机,其中第i个台挤奶机生产M_i单位(1 <= M_i<=10,000)的牛奶. 保罗计划切断一段连续的挤奶机,从第i台挤奶机到第j台挤奶机(2<= i<= j<= N-1).注意,他不希望断开第一台或最后一台挤奶机,因为这将会使他的计划太容易被发现.保罗的目标是让其余机器的平均…

先二分答案m, 然后对于原序列 A[i] = A[i] - m,  然后O(n)找最大连续子序列和, 那么此时序列由 L + mx + R组成. L + mx + R = sum - n * m, sum为原序列的和. 假如二分的答案m是可行的, 那么 L + R = sum - n * m - mx 应该 <= 0 ------------------------------------------------------------------------------------- #inc…

传送门:Sabotage 题意:给定多个城市的网络,每个城市之间的通信有花费,要求使得首都和最大城市之间的通信断掉的最小花费.要求输出任意一组砸掉的边. 分析:跑一遍最大流dinic后,根据最小割定理,整部图被分为S,T两部分,从源点出发dfs得到S集的点,剩下的为T集的点,然后输出左右两边各一个连着的点就是割边. #pragma comment(linker,"/STACK:1024000000,1024000000") #include <cstdio> #includ…

https://www.luogu.org/problem/show?pid=2115 题目描述 Farmer John's arch-nemesis, Farmer Paul, has decided to sabotage Farmer John's milking equipment! The milking equipment consists of a row of N (3 <= N <= 100,000) milking machines, where the ith machi…

题目描述 Farmer John's arch-nemesis, Farmer Paul, has decided to sabotage Farmer John's milking equipment! The milking equipment consists of a row of N (3 <= N <= 100,000) milking machines, where the ith machine produces M_i units of milk (1 <= M_i &…

科学二分姿势 Description Farmer John's arch-nemesis, Farmer Paul, has decided to sabotage Farmer John's milking equipment! The milking equipment consists of a row of N (3 <= N <= 100,000) milking machines, where the ith machine produces M_i units of milk…