Description We are supposed to make a budget proposal for this multi-site competition. The budget proposal is a matrix where the rows represent different kinds of expenses and the columns represent different sites. We had a meeting about this, some t…

"Oh, There is a bipartite graph.""Make it Fantastic."X wants to check whether a bipartite graph is a fantastic graph. He has two fantastic numbers, and he wants to let all the degrees to between the two boundaries. You can pick up seve…

https://nanti.jisuanke.com/t/31447 题意 一个二分图,左边N个点,右边M个点,中间K条边,问你是否可以删掉边使得所有点的度数在[L,R]之间 分析 最大流不太会.. 贪心做法: 考虑两个集合A和B,A为L<=d[i]<=R,B为d[i]>R 枚举每个边 1.如果u和v都在B集合,直接删掉2.如果u和v都在A集合,无所谓3.如果u在B,v在A,并且v可删边即d[v]>L4.如果u在A,v在B,并且u可删边即d[u]>L 最后枚举N+M个点判断是…

UVALive-7670 ICPC北京2016-C题 hihocoder 1424 题意 有个 \(N\times N\) 的棋盘,告诉你每个格子黑色(1)或白色(0),以及每对能相互交换的同行或同列格子,每个格子只在一对中,即共有\(N\times N /2\)对.求最少交换次数使得每行每列的黑格子总数满足给出的上下范围:若最终第i行,第j列分别有\(R[i],C[j]\)个黑格子,那么需要让\(Rl[i]\le R[i]\le Rh[i],Cl[j]\le C[i]\le Ch[j]\).…

题目链接: http://www.lydsy.com:808/JudgeOnline/problem.php?id=3876 题目大意: 给定一张拓扑图(有向无环图),每条边有边权,每次只能从第一个点出发沿着拓扑图走一条路径,求遍历所有边所需要的最小边权和. 题目思路: [有源汇上下界费用流] Orz两位神犇,以下思路借鉴自 http://hzwer.com/6224.html http://blog.csdn.net/popoqqq/article/details/43024221 建图如下:…

http://fastvj.rainng.com/contest/236779#problem/G Description: n 行 m 列 给你行和 与 列和 然后有Q个限制,表示特定单元格元素大小的范围,最后问你可行的矩阵值 Solution: 有源汇上下界最大流问题,初始源点 连 行和流量是该行对应得行和,然后列连初始汇点,容量为列的列和,详细的限制,对应于行列之间,因为我最后要输出一个矩阵,所以n * m每一条边都要链接最后,手动连一条 t s inf的边,变成无源汇有上下界可行流问题,…

http://www.lydsy.com/JudgeOnline/problem.php?id=2055 某个国家必须经过vi次, 可以转化为上下界都为vi的边 对这张图做有源汇上下界可行最小费用流 按无源汇上下界可行流建好图,跑超级源点到超级汇点的最小费用最大流即可 #include<cstdio> #include<cstring> #include<iostream> #include<algorithm> using namespace std; #…

Shoot the Bullethttp://acm.zju.edu.cn/onlinejudge/showProblem.do?problemId=3442 Time Limit: 2 Seconds      Memory Limit: 32768 KB      Special Judge Gensokyo is a world which exists quietly beside ours, separated by a mystical border. It is a utopia…

描述 ensokyo is a world which exists quietly beside ours, separated by a mystical border. It is a utopia where humans and other beings such as fairies, youkai(phantoms), and gods live peacefully together. Shameimaru Aya is a crow tengu with the ability…

题目链接: http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemCode=3229 题目大意: n天给m个女孩拍照(1<=n<=365,1<=m<=1000),每个女孩X在n天里总共至少拍Gx张照片. 第k天可以给Ck个女孩拍照,当天总共最多拍Dk张照片,每个女孩这天被拍的数量在[Li,Ri]. 满足要求的条件下尽量多拍照. 求是否有可行解,没有输出-1,有的话输出最大流以及每天对该天能拍照的女孩的拍照数量(巨坑..怪我没…