随笔分类 -  图论(集合)

二分,网络流,费用流,连通图,拓扑等等
摘要:“网络流博大精深”—sideman语 最早知道网络流的内容便是最大流问题,最大流问题很好理解: 解释一定要通俗! 如右图所示,有一个管道系统,节点{1,2,3,4},有向管道{A,B,C,D,E},即有向图一张. [1]是源点,有无限的水量,[4]是汇点,管道容量如图所示.试问[4]点最大可接收的 阅读全文
posted @ 2015-08-02 11:36 柳下_MBX 阅读(272) 评论(0) 推荐(0)
摘要:Drainage Ditches Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 62078 Accepted: 23845 Description Every time it rains on Farmer John's fie 阅读全文
posted @ 2015-08-02 11:35 柳下_MBX 阅读(201) 评论(0) 推荐(0)
摘要:D - Black Spot Time Limit:1000MS Memory Limit:65536KB 64bit IO Format:%I64d & %I64uSubmit Status Practice URAL 1934Description Bootstrap: Jones's terr... 阅读全文
posted @ 2015-07-29 10:44 柳下_MBX 阅读(254) 评论(0) 推荐(0)
摘要:Drainage Ditches Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 11744 Accepted Submission(s): 55 阅读全文
posted @ 2015-07-27 10:39 柳下_MBX 阅读(233) 评论(0) 推荐(0)
摘要:EdmondsKarp算法,简称EK算法,O(m^2n) 因为是初学教程,所以我会尽量避免繁杂的数学公式和证明。也尽量给出了较为完整的代码。 本文的目标群体是网络流的初学者,尤其是看了各种NB的教程也没看懂怎么求最大流的小盆友们。本文的目的是,解释基本的网络流模型,最基础的最大流求法,即bfs找增广 阅读全文
posted @ 2015-07-27 10:34 柳下_MBX 阅读(525) 评论(0) 推荐(0)
摘要:欢迎参加——BestCoder周年纪念赛(高质量题目+多重奖励) Flow Problem Time Limit: 5000/5000 MS (Java/Others) Memory Limit: 65535/32768 K (Java/Others)Total Submission(s): 101 阅读全文
posted @ 2015-07-27 10:33 柳下_MBX 阅读(219) 评论(0) 推荐(0)
摘要:Antenna PlacementTime Limit: 1000MSMemory Limit: 65536KTotal Submissions: 7329Accepted: 3635DescriptionThe Global Aerial Research Centre has been allo... 阅读全文
posted @ 2015-07-22 10:46 柳下_MBX 阅读(1078) 评论(0) 推荐(0)
摘要:AsteroidsTime Limit: 1000MSMemory Limit: 65536KTotal Submissions: 17237td>Accepted: 9375DescriptionBessie wants to navigate her spaceship through a d... 阅读全文
posted @ 2015-07-22 09:47 柳下_MBX 阅读(219) 评论(0) 推荐(0)
摘要:Girls and BoysTime Limit: 20000/10000 MS (Java/Others)Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 8473Accepted Submission(s): 3893Pr... 阅读全文
posted @ 2015-07-22 09:27 柳下_MBX 阅读(321) 评论(0) 推荐(0)
摘要:欢迎参加——BestCoder周年纪念赛(高质量题目+多重奖励)Air RaidTime Limit: 2000/1000 MS (Java/Others)Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 3841Accept... 阅读全文
posted @ 2015-07-22 09:08 柳下_MBX 阅读(348) 评论(0) 推荐(0)
摘要:二分图多重匹配问题#include #include #include #include using namespace std;const int maxn = 100005;const int maxm = 15;int cap[maxm];int Link[maxm][maxn];int vL... 阅读全文
posted @ 2015-07-21 20:21 柳下_MBX 阅读(330) 评论(0) 推荐(0)
摘要:二分图又称作二部图,是图论中的一种特殊模型。 设G=(V,E)是一个无向图,如果顶点V可分割为两个互不相交的子集(A,B),并且图中的每条边(i,j)所关联的两个顶点i和j分别属于这两个不同的顶点集(i in A,j in B),则称图G为一个二分图。二分图的最大匹配:匈牙利算法完美匹配: 如果所... 阅读全文
posted @ 2015-07-21 20:08 柳下_MBX 阅读(1342) 评论(0) 推荐(0)
摘要:最小顶点覆盖==二分图的最大匹配最少路径覆盖==n—最大匹配////n为左右集合中的顶点个数最大点独立集 = 顶点共个数 - 匹配顶点数多个环的并 例如:有n个国家,国家之间通过有向边相连,边有权值, 现在让你把所有的国家都划成一个一个的圈,使得所有圈的总权值和最大。 二分图的实质就是多个环,... 阅读全文
posted @ 2015-07-21 10:51 柳下_MBX 阅读(397) 评论(0) 推荐(0)
摘要:确定比赛名次 Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 15603 Accepted Submission(s): 6224 Problem 阅读全文
posted @ 2015-07-11 13:09 柳下_MBX 阅读(276) 评论(0) 推荐(0)
摘要:Sorting It All Out Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 29744 Accepted: 10293 Description An ascending sorted sequence of distin 阅读全文
posted @ 2015-07-11 12:27 柳下_MBX 阅读(186) 评论(0) 推荐(0)
摘要:Wormholes Time Limit: 2000MS Memory Limit: 65536K Total Submissions: 35103 Accepted: 12805 Description While exploring his many farms, Farmer John has 阅读全文
posted @ 2015-07-10 00:29 柳下_MBX 阅读(139) 评论(0) 推荐(0)
摘要:Frogger Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 28825 Accepted: 9359 Description Freddy Frog is sitting on a stone in the middle of 阅读全文
posted @ 2015-07-10 00:04 柳下_MBX 阅读(182) 评论(0) 推荐(0)
摘要:Currency Exchange Time Limit: 1000MS Memory Limit: 30000K Total Submissions: 22123 Accepted: 7990 Description Several currency exchange points are wor 阅读全文
posted @ 2015-07-09 16:41 柳下_MBX 阅读(333) 评论(0) 推荐(0)
摘要:#include<iostream>#include<cstdio>#include<utility>#include<queue>#include<cstring>using namespace std;#define INF 1000000000int d[20005];int n,m,a,b, 阅读全文
posted @ 2015-07-09 15:28 柳下_MBX 阅读(191) 评论(0) 推荐(0)
摘要:Arbitrage Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 17360 Accepted: 7308 Description Arbitrage is the use of discrepancies in currenc 阅读全文
posted @ 2015-07-04 19:13 柳下_MBX 阅读(191) 评论(0) 推荐(0)