链接:poj 1466 题意:有n个学生,每一个学生都和一些人有关系,如今要你找出最大的人数.使得这些人之间没关系 思路:求最大独立集,最大独立集=点数-最大匹配数 分析:建图时应该是一边是男生的点,一边是女生的点连边.可是题目中没说性别的问题.仅仅能将每一个点拆成两个点.一个当作是男的点,一个当作是女的点了,然后连边.因为关系是相互的.这样就造成了边的反复.也就是边集是刚才的二倍,从而导致了最大匹配变成了原本的二倍.因此,此时最大独立集=点数-最大匹配数/2. #include<stdio.h…

Girls and Boys Time Limit: 1 Sec  Memory Limit: 256 MB 题目连接 http://poj.org/problem?id=1466 Description In the second year of the university somebody started a study on the romantic relations between the students. The relation "romantically involved&q…

题目链接:http://poj.org/problem?id=1466 Girls and Boys Time Limit: 5000MS   Memory Limit: 10000K Total Submissions: 12026   Accepted: 5355 Description In the second year of the university somebody started a study on the romantic relations between the stu…

http://poj.org/problem?id=1466 Girls and Boys Time Limit: 5000MS   Memory Limit: 10000K Total Submissions: 11085   Accepted: 4956 Description In the second year of the university somebody started a study on the romantic relations between the students…

Girls and Boys Time Limit: 1 Sec  Memory Limit: 256 MB 题目连接 http://poj.org/problem?id=1466 Description In the second year of the university somebody started a study on the romantic relations between the students. The relation "romantically involved&q…

[题目链接] http://poj.org/problem?id=1466 [题目大意] 给出一些人和他们所喜欢的人,两个人相互喜欢就能配成一对, 问最后没有配对的人的最少数量 [题解] 求最少数量,就是最多匹配的补集,因此做一遍二分图匹配即可. [代码] #include <cstdio> #include <algorithm> #include <cstring> #include <vector> using namespace std; const…

Girls and Boys Time Limit: 5000MS   Memory Limit: 10000K Total Submissions: 10912   Accepted: 4887 Description In the second year of the university somebody started a study on the romantic relations between the students. The relation "romantically in…

http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemId=137 http://poj.org/problem?id=1466 题目大意: n个学生,他们中有的有关系,有的没有关系,求最多可以取出几个人,使得他们之间没有关系. 思路: 复制别人的..... 最大独立集问题:在N个点的图G中选出m个点,使这m个点两两之间没有边．求m最大值．如果图G满足二分图条件,则可以用二分图匹配来做．最大独立集点数 = N - 最大匹配数/2,然后就是…

Girls and Boys Time Limit: 5000ms Memory Limit: 10000KB This problem will be judged on PKU. Original ID: 1466 64-bit integer IO format: %lld      Java class name: Main In the second year of the university somebody started a study on the romantic(浪漫的)…

题目描述: 给出一系列男女配对意愿信息.求一个集合中的最大人数,满足这个集合中两两的人不能配对. /* 二分图的最大独立集 因为没有给出具体的男生和女生,所以可以将数据扩大一倍,即n个男生,n个女生, 根据定理,最大独立集=总数-匹配数(本题应该除以2) */ #include<cstdio> #include<iostream> #include<cstring> #define N 510 using namespace std; int a[N][N],used[…

有n个人, 其中有男生和女生,接着有n行,分别给出了每一个人暗恋的对象(不止暗恋一个) 现在要从这n个人中找出一个最大集合,满足这个集合中的任意2个人,都没有暗恋这种关系. 输出集合的元素个数. 刚开始想,把人看成顶点,若有暗恋的关系,就连一条边,构成一个图 独立集的概念:一个图中两两互不相连的顶点集合 所以这道题,就是要求最大独立集 有:最大独立集+最小顶点覆盖=|V|(顶点的总个数) 那就求最小顶点覆盖了 根据题意: 暗恋的对象性别不同,所以a暗恋b,b暗恋c,c暗恋a这种关系不可能存在 也…

#include<iostream> #include<stdio.h> #define MAXN 505 using namespace std; int edge[MAXN][MAXN]; int match[MAXN]; bool ck[MAXN]; int hungary(int num1,int num2); bool search_dfs(int num1,int num2,int value); int main() { //freopen("acm.acm…

Description In the second year of the university somebody started a study on the romantic relations between the students. The relation "romantically involved" is defined between one girl and one boy. For the study reasons it is necessary to find…

题意:n个学生,给你每个学生浪漫的学生学号(男女之间浪漫),问你找出一个最大的集合保证集合内的任意两个学生之间没有相互浪漫关系,输出最大集合的人数. 注意:这里的浪漫边是双向的,如果1对2浪漫, 那么2对1也浪漫,题意好像没说清楚, 但我测了一下,是双向边. 思路:最大独立集和最小点覆盖集是互补的,所以 最大独立集 == 总人数n - 最小点覆盖集, 如果题目给你的是二分图那么直接二分匹配一下即可,但这题不是二分图,我们抓住双向边,那么我们进行拆点, 做一次匹配,求出来的匹配数是(左边男生匹配右…

#include <iostream> #include <memory.h> #include <cstdio> using namespace std; int c; ; int visit[maxn],map[maxn][maxn],link[maxn]; bool DFS(int a) { ;i<c;i++) { if(!visit[i] && map[a][i]) { visit[i]=; || DFS(link[i])) { link[…

#include<stdio.h> #include<string.h>//这个分开后男的站在一边女的站在一边,不肯能有les或者gay.最大独立集=n-最大匹配数 #define  N  510 int map[N][N],n,mark[N],link[N]; int find(int u) {  int i;  for(i=0;i<=n;i++)  if(!mark[i]&&map[u][i]) {     mark[i]=1;     if(link[i…

思路:匈牙利 n-ans/2; // by SiriusRen #include <cstdio> #include <cstring> #define N 505 using namespace std; int jy,xx,yy,n,tot,ans; int first[N],next[N*N],v[N*N],mat[N]; bool vis[N]; void add(int x,int y){v[tot]=y,next[tot]=first[x],first[x]=tot++…

标题效果:有着n学生,有一些同学之间的特殊关系.. .为了一探究竟m学生.要求m免两者之间的学生有没有这样的特殊关系 解决问题的思路:二分图的问题,殊关系是对称的.所以能够将两个点集都设置为n个点.求出最大匹配后再除以2就可以得到(由于关系是对称的.所以所求得的最大匹配是双倍的) 得到最大匹配了,能够由定理得到 最大独立集 ＝ n - 最大匹配数 #include<cstdio> #include<vector> #include<cstring> using name…

Problem DescriptionIn the second year of the university somebody started a study on the romantic relations between the students. The relation "romantically involved" is defined between one girl and one boy. For the study reasons it is necessary…

Girls and Boys Time Limit: 5000MS   Memory Limit: 10000K Total Submissions: 11694   Accepted: 5230 Description In the second year of the university somebody started a study on the romantic relations between the students. The relation "romantically in…

Girls and Boys Time Limit: 5000MS   Memory Limit: 10000K Total Submissions: 11097   Accepted: 4960 Description In the second year of the university somebody started a study on the romantic relations between the students. The relation "romantically in…

POJ图论分类[转] 一个很不错的图论分类,非常感谢原版的作者!!!在这里分享给大家,爱好图论的ACMer不寂寞了... (很抱歉没有找到此题集整理的原创作者,感谢知情的朋友给个原创链接) POJ:http://poj.org/ 1062* 昂贵的聘礼 枚举等级限制+dijkstra 1087* A Plug for UNIX 2分匹配 1094 Sorting It All Out floyd 或 拓扑 1112* Team Them Up! 2分图染色+DP 1125 Stockbroker…

Halloween treats Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 7644   Accepted: 2798   Special Judge Description Every year there is the same problem at Halloween: Each neighbour is only willing to give a certain total number of sweets…

Find a multiple Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 7192   Accepted: 3138   Special Judge Description The input contains N natural (i.e. positive integer) numbers ( N <= 10000 ). Each of that numbers is not greater than 15000…

The Pilots Brothers' refrigerator Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 22286   Accepted: 8603   Special Judge Description The game “The Pilots Brothers: following the stripy elephant” has a quest where a player needs to open a…

Flip Game Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 37427   Accepted: 16288 Description Flip game is played on a rectangular 4x4 field with two-sided pieces placed on each of its 16 squares. One side of each piece is white and the…

Corn Fields Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 9806   Accepted: 5185 Description Farmer John has purchased a lush new rectangular pasture composed of M by N (1 ≤ M ≤ 12; 1 ≤ N ≤ 12) square parcels. He wants to grow some yumm…

Sum of Consecutive Prime Numbers Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 20050   Accepted: 10989 Description Some positive integers can be represented by a sum of one or more consecutive prime numbers. How many such representatio…

Tree Recovery Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 11939   Accepted: 7493 Description Little Valentine liked playing with binary trees very much. Her favorite game was constructing randomly looking binary trees with capital le…

Seek the Name, Seek the Fame Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 17898   Accepted: 9197 Description The little cat is so famous, that many couples tramp over hill and dale to Byteland, and asked the little cat to give names t…