zoukankan      html  css  js  c++  java
  • HDU 1083 Courses

    http://acm.hdu.edu.cn/showproblem.php?pid=1083

    Problem Description
    Consider a group of N students and P courses. Each student visits zero, one or more than one courses. Your task is to determine whether it is possible to form a committee of exactly P students that satisfies simultaneously the conditions:

    . every student in the committee represents a different course (a student can represent a course if he/she visits that course)

    . each course has a representative in the committee

    Your program should read sets of data from a text file. The first line of the input file contains the number of the data sets. Each data set is presented in the following format:

    P N
    Count1 Student1 1 Student1 2 ... Student1 Count1
    Count2 Student2 1 Student2 2 ... Student2 Count2
    ...... 
    CountP StudentP 1 StudentP 2 ... StudentP CountP

    The first line in each data set contains two positive integers separated by one blank: P (1 <= P <= 100) - the number of courses and N (1 <= N <= 300) - the number of students. The next P lines describe in sequence of the courses . from course 1 to course P, each line describing a course. The description of course i is a line that starts with an integer Count i (0 <= Count i <= N) representing the number of students visiting course i. Next, after a blank, you'll find the Count i students, visiting the course, each two consecutive separated by one blank. Students are numbered with the positive integers from 1 to N.

    There are no blank lines between consecutive sets of data. Input data are correct.

    The result of the program is on the standard output. For each input data set the program prints on a single line "YES" if it is possible to form a committee and "NO" otherwise. There should not be any leading blanks at the start of the line.

    An example of program input and output:
     
    Sample Input
    2 3 3 3 1 2 3 2 1 2 1 1 3 3 2 1 3 2 1 3 1 1
     
    Sample Output
    YES NO

    代码:

    #include <bits/stdc++.h>
    using namespace std;
    
    const int maxn = 2010;
    int T, N, M;
    int mp[maxn][maxn];
    int vis[maxn], match[maxn];
    
    bool path(int u) {
        for(int v = 1; v <= N; v ++) {
            if(mp[u][v] && !vis[v]) {
                vis[v] = 1;
                if(match[v] == -1 || path(match[v])) {
                    match[v] = u;
                    return true;
                }
            }
        }
        return false;
    }
    
    int main() {
        scanf("%d", &T);
        while(T --) {
            memset(mp, 0, sizeof(mp));
            memset(match, -1, sizeof(match));
            scanf("%d%d", &M, &N);
            for(int i = 1; i <= M; i ++) {
                int K;
                scanf("%d", &K);
                for(int k = 0; k < K; k ++) {
                    int x;
                    scanf("%d", &x);
                    mp[i][x] = 1;
                }
            }
            int cnt = 0;
            for(int i = 1; i <= M; i ++) {
                memset(vis, 0, sizeof(vis));
                if(path(i)) cnt ++;
            }
            if(cnt != M) printf("NO
    ");
            else printf("YES
    ");
        }
        return 0;
    }
    

      匈牙利算法 求最大匹配值 开始的时候 WA 因为把学生人数和课程数搞反了

  • 相关阅读:
    latin1字符集的数据转换为utf8字符集
    mysql使用utf8mb4经验吐血总结
    字符集GBK和UTF8的区别说明
    10分钟学会理解和解决MySQL乱码问题
    MySQL大小写敏感总结
    分区表基本类型
    form表单提交的几种方法
    Redis面试题及分布式集群
    ELK
    Linux下的crontab定时执行任务命令详解
  • 原文地址:https://www.cnblogs.com/zlrrrr/p/10669923.html
Copyright © 2011-2022 走看看