zoukankan      html  css  js  c++  java
  • Girls and Boys

    Girls and Boys

    Time Limit: 20000/10000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
    Total Submission(s): 5565    Accepted Submission(s): 2481

     

    Problem Description
    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 out the maximum set satisfying the condition: there are no two students in the set who have been “romantically involved”. The result of the program is the number of students in such a set.

     

    The input contains several data sets in text format. Each data set represents one set of subjects of the study, with the following description:

     

    the number of students
    the description of each student, in the following format
    student_identifier:(number_of_romantic_relations) student_identifier1 student_identifier2 student_identifier3 ...
    or
    student_identifier:(0)

     

    The student_identifier is an integer number between 0 and n-1, for n subjects.
    For each given data set, the program should write to standard output a line containing the result.
     

     

    Sample Input
    7
    0: (3) 4 5 6
    1: (2) 4 6
    2: (0)
    3: (0)
    4: (2) 0 1
    5: (1) 0
    6: (2) 0 1
    3
    0: (2) 1 2
    1: (1) 0
    2: (1) 0
     

     

    Sample Output
    5
    2
     

     

    Source
    Southeastern Europe 2000
     

     

    Recommend
    JGShining

    嗯,看起来是个求最大独立集的题,而且还是个二分图.因为题里没说有Homosexuality,所以不会有奇环.不过图是用一般形式给出的算出来的匹配要除以2.

     

    #include<stdio.h>
    #include<string.h>
    int n,m,match[1024];
    bool visit[1024],G[1024][1024];
    bool DFS(int k)
    {
        int t;
        for (int i=0;i<m;i++)
        if (G[k][i] && !visit[i])
        {
            visit[i]=1;
            t=match[i];
            match[i]=k;
            if (t==-1 || DFS(t)) return true;
            match[i]=t;
        }
        return false;
    }
    int Max_match()
    {
        int ans=0;
        memset(match,-1,sizeof(match));
        for (int i=0;i<n;i++)
        {
            memset(visit,0,sizeof(visit));
            if (DFS(i)) ans++;
        }
        return ans;
    }
    int main()
    {
        int t,a,b,c;
        while (scanf("%d",&t)!=EOF)
        {
            n=m=t;
            memset(G,0,sizeof(G));
            while (t--)
            {
                scanf("%d: (%d)",&a,&b);
                for (int i=0;i<b;i++)
                {
                    scanf("%d",&c);
                    G[a][c]=1;
                }
            }
            printf("%d
    ",n-Max_match()/2);
        }
    }

     

     

     

  • 相关阅读:
    ASP下的URL重写
    经典日历
    asp中使用存储过程
    带进度条的ASP无组件断点续传下载代码
    XML与ASP简单结合实现HTML模板功能
    ASP函数
    CSS垂直树形下拉列表
    ASP无组件上载,带进度条,多文件上载。。
    采用AJAX实现带进度条的文件上传
    Rose与PowerDesigner:两款建模工具对比分析比较
  • 原文地址:https://www.cnblogs.com/dramstadt/p/3193218.html
Copyright © 2011-2022 走看看