机器调度与委员会形成算法-优快云博客

2题都是匈牙利算法板题，放一起了
http://poj.org/problem?id=1325
As we all know, machine scheduling is a very classical problem in computer science and has been studied for a very long history. Scheduling problems differ widely in the nature of the constraints that must be satisfied and the type of schedule desired. Here we consider a 2-machine scheduling problem.

There are two machines A and B. Machine A has n kinds of working modes, which is called mode_0, mode_1, …, mode_n-1, likewise machine B has m kinds of working modes, mode_0, mode_1, … , mode_m-1. At the beginning they are both work at mode_0.

For k jobs given, each of them can be processed in either one of the two machines in particular mode. For example, job 0 can either be processed in machine A at mode_3 or in machine B at mode_4, job 1 can either be processed in machine A at mode_2 or in machine B at mode_4, and so on. Thus, for job i, the constraint can be represent as a triple (i, x, y), which means it can be processed either in machine A at mode_x, or in machine B at mode_y.

Obviously, to accomplish all the jobs, we need to change the machine’s working mode from time to time, but unfortunately, the machine’s working mode can only be changed by restarting it manually. By changing the sequence of the jobs and assigning each job to a suitable machine, please write a program to minimize the times of restarting machines.
Input
The input file for this program consists of several configurations. The first line of one configuration contains three positive integers: n, m (n, m < 100) and k (k < 1000). The following k lines give the constrains of the k jobs, each line is a triple: i, x, y.

The input will be terminated by a line containing a single zero.
Output
The output should be one integer per line, which means the minimal times of restarting machine.
Sample Input
5 5 10
0 1 1
1 1 2
2 1 3
3 1 4
4 2 1
5 2 2
6 2 3
7 2 4
8 3 3
9 4 3
0
Sample Output
3

#include<stdio.h>
#include<string.h>
#define N 105
using namespace std;
int vis[N],pre[N],map[N][N];
int n,m,k,j,a,b;
int dfs(int x)
{
	for(int i=0;i<m;i++)
	{
		if(map[x][i]&&!vis[i])
		{
			vis[i]=1;
			if(pre[i]==0||dfs(pre[i]))
			{
				pre[i]=x;
				return 1;
			}			
		}
	}
	return 0;
}
int main()
{
	while(~scanf("%d",&n))
	{
		if(n==0)
		break;
		scanf("%d%d",&m,&k);
        memset(map,0,sizeof(map));
        memset(pre,0,sizeof(pre));
	    while(k--)
	    {
		    scanf("%d%d%d",&j,&a,&b);
		    if(a&&b) 
			map[a][b]=1;
	    }	
	    int ans=0;
	    for(int i=0;i<n;i++)
	    {
		    memset(vis,0,sizeof(vis));
		    if(dfs(i)==1)
		    ans++;
	    }
	    printf("%d\n",ans);
	}
}

http://poj.org/problem?id=1469
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
Input
Your program should read sets of data from the std input. The first line of the input contains the number of the data sets. Each data set is presented in the following format:

P N
Count1 Student 1 1 Student 1 2 … Student 1 Count1
Count2 Student 2 1 Student 2 2 … Student 2 Count2
…
CountP Student P 1 Student P 2 … Student P 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抣l 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.
Output
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.
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

#include<stdio.h>
#include<string.h>
using namespace std;
int map[305][305],vis[305],pre[305];
int n,p,ca;
int dfs(int x)
{
	for(int i=1;i<=n;i++)
	{
		if(map[x][i]&&!vis[i])
		{
			vis[i]=1;
			if(pre[i]==0||dfs(pre[i]))
			{
				pre[i]=x;
				return 1;
			}			
		}
	}
	return 0;
}
int main()
{
	scanf("%d",&ca);
	while(ca--)
	{
		scanf("%d%d",&p,&n);
        memset(map,0,sizeof(map));
        memset(pre,0,sizeof(pre));
	    for(int i=1;i<=p;i++)
		{
			int num;
			scanf("%d",&num);
			for(int j=0;j<num;j++)
			{
				int temp;
				scanf("%d",&temp);
				map[i][temp]=1;
			}
		}	
	    int ans=0;
	    for(int i=1;i<=n;i++)
	    {
		    memset(vis,0,sizeof(vis));
		    if(dfs(i)==1)
		    ans++;
	    }
	    if(ans==p)
	    printf("YES\n");
	    else
	    printf("NO\n");
	}
}