HDU 1150 Machine Schedule (minimum vertex overlay)

pid=1150 ">machine ScheduleTime limit:2000/1000 MS (java/others) Memory limit:65536/32768 K (java/others)
Total submission (s): 5424 Accepted Submission (s): 2691


Problem Descriptionas We all know, machine scheduling are a very classical problem in computer science and have 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 was machines a and B. Machine A have n kinds of working modes, which is called Mode_0, Mode_1, ..., mode_n-1, Likew Ise machine B has m kinds of working modes, MODE_0, Mode_1, ..., mode_m-1. At the beginning they is both work at Mode_0.

For k jobs given, each of the them can is processed in either one of the one of the both machines in particular mode. For example, job 0 can either is processed in machine A at mode_3 or in machine B at Mode_4, Job 1 can either be processed In machine A is mode_2 or in machine B at Mode_4, and so on. Thus, for Job I, the constraint can is represent as a triple (I, X, y), which means it can be processed either 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 is 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.

Inputthe input file for this program consists of several configurations. The first line of one configuration contains three positive integers:n, M (N, M <) and K (K < 1000). The following k lines give the constrains of the K jobs, each of which is a triple:i, X, Y.

The input would be terminated to a line containing a single zero.

Outputthe output should is one integer per line, which means the minimal times of restarting machine.

Sample Input

5 5 100 1 11 1 22 1 33 1 44 2 15 2 26 2 37 2 48 3 39 4 30

Sample Output

3

 Test Instructions: There is a, b two machines. Each machine has multiple states, each of which can complete a task. The minimum state required to complete some work.

Minimum vertex overlay: Includes a collection of part vertices of the x, y portion of the binary graph, so that all edges have at least one vertex within that point set.

Minimum vertex overlay = Two maximum match of the graph

 #include "    Stdio.h "#include" string.h "#define N 105int g[n][n];int link[n],mark[n],n,m;int find (int k) {int i;            for (i=1;i<m;i++) {if (!mark[i]&&g[k][i]) {mark[i]=1; if (!link[i]| |                Find (Link[i])) {link[i]=k;            return 1; }}} return 0;}    int main () {int i,a,b,c,k;        while (scanf ("%d", &n), N) {memset (g,0,sizeof (g));        memset (link,0,sizeof (link));        scanf ("%d%d", &m,&k);            while (k--) {scanf ("%d%d%d", &c,&a,&b);            if (a&&b)//Start state does not need to convert {g[a][b]=1;        }} int ans=0;            for (i=1;i<n;i++) {memset (mark,0,sizeof (Mark));        Ans+=find (i);    } printf ("%d\n", ans); } return 0;} 

HDU 1150 Machine Schedule (minimum vertex overlay)