POJ2771_Guardian of Decency(二分圖/最大獨立集=N-最大比對)

解題報告

http://blog.csdn.net/juncoder/article/details/38159017

題目傳送門

題意：

看到題目我就笑了，，，

老師認為這樣的兩個學生不是一對：

身高相差40以上（年齡都不是距離了，身高又算什麼）

不同性别（sad，，，就不允許基友存在呀，，，誰的肥皂掉了，，，）

喜歡不一樣的歌曲類型（你總不能要求兩人整天聽小蘋果吧,,,,,,你是我的小丫小蘋果,,,,,,）

喜歡一樣的運動（ they are likely to be fans of different teams and that would result in fighting......這是什麼理由，喜歡同個不同球隊還會打起來）

問最多的不在一起的有多少人

思路：

不在一起代表獨立于相愛關系的，也就是求最大獨立集，集合裡面任意兩個人都不相愛

最大獨立集=結點數-最大比對

ps不知道是不是寫挫了，重寫才過，sad。。。

#include <cmath>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
struct node
{
    int h;
    char sex;
    char mus[110];
    char spo[110];
}M[510],F[510];
int n,m,f,mmap[550][550],pre[550],vis[550];
int pd(int i,int j)
{
    if( abs(M[i].h - F[j].h) > 40 )
        return 0;
    if( strcmp(M[i].mus,F[j].mus) )
        return 0;
    if( strcmp(M[i].spo,F[j].spo) == 0 )
        return 0;
    return 1;
}
int dfs(int x)
{
    for(int i=m+1;i<=m+f;i++){
        if(!vis[i]&&mmap[x][i]){
            vis[i]=1;
            if(pre[i]==-1||dfs(pre[i])){
                pre[i]=x;
                return 1;
            }
        }
    }
    return 0;
}
int main()
{
    int i,j,t,h;
    char str[100];
    scanf("%d",&t);
    while(t--){
        scanf("%d",&n);
        m=f=1;
        memset(mmap,0,sizeof(mmap));
        memset(pre,-1,sizeof(pre));
        memset(M,0,sizeof(M));
        memset(F,0,sizeof(F));
        for(i=1;i<=n;i++){
            scanf("%d%s",&h,str);
            if(str[0]=='M'){
                scanf("%s%s",M[m].mus,M[m].spo);
                M[m].h=h;
                M[m++].sex='M';
            }
            else {
                scanf("%s%s",F[f].mus,F[f].spo);
                F[f].h=h;
                F[f++].sex='F';
            }
        }
        for(i=1;i<=m;i++){
            for(j=1;j<=f;j++){
                if(pd(i,j))
                mmap[i][m+j]=1;
            }
        }
        int ans=0;
        for(i=1;i<=m;i++){
            memset(vis,0,sizeof(vis));
            ans+=dfs(i);
        }
        printf("%d\n",n-ans);
    }
}
           

Guardian of Decency

Time Limit: 3000MS	Memory Limit: 65536K
Total Submissions: 4876	Accepted: 2056

Description

Frank N. Stein is a very conservative high-school teacher. He wants to take some of his students on an excursion, but he is afraid that some of them might become couples. While you can never exclude this possibility, he has made some rules that he thinks indicates a low probability two persons will become a couple: 

• Their height differs by more than 40 cm. 
• They are of the same sex. 
• Their preferred music style is different. 
• Their favourite sport is the same (they are likely to be fans of different teams and that would result in fighting).

So, for any two persons that he brings on the excursion, they must satisfy at least one of the requirements above. Help him find the maximum number of persons he can take, given their vital information. 

Input

The first line of the input consists of an integer T ≤ 100 giving the number of test cases. The first line of each test case consists of an integer N ≤ 500 giving the number of pupils. Next there will be one line for each pupil consisting of four space-separated data items: 

• an integer h giving the height in cm; 
• a character 'F' for female or 'M' for male; 
• a string describing the preferred music style; 
• a string with the name of the favourite sport.

No string in the input will contain more than 100 characters, nor will any string contain any whitespace. 

Output

For each test case in the input there should be one line with an integer giving the maximum number of eligible pupils.

Sample Input

2
4
35 M classicism programming
0 M baroque skiing
43 M baroque chess
30 F baroque soccer
8
27 M romance programming
194 F baroque programming
67 M baroque ping-pong
51 M classicism programming
80 M classicism Paintball
35 M baroque ping-pong
39 F romance ping-pong
110 M romance Paintball
      

Sample Output

3
7