hdu 1150 最小点覆盖

 1 #include<cstdio>
 2 #include<algorithm>
 3 #include<cstring>
 4 using namespace std;
 5 const int MAXN = 510;
 6 int uN,vN;//u,v的数目，使用前面必须赋值
 7 int g[MAXN][MAXN];//邻接矩阵
 8 int linker[MAXN];
 9 bool used[MAXN];
10 bool dfs(int u)
11 {
12     for(int v = 0; v < vN;v++)
13     if(g[u][v] && !used[v])
14     {
15         used[v] = true;
16         if(linker[v] == -1 || dfs(linker[v]))
17         {
18             linker[v] = u;
19             return true;
20         }
21     }
22     return false;
23 }
24 int hungary()
25 {
26     int res = 0;
27     memset(linker,-1,sizeof(linker));
28     for(int u = 0;u < uN;u++)
29     {
30         memset(used,false,sizeof(used));
31         if(dfs(u))res++;
32     }
33     return res;
34 }
35 int main()
36 {
37     int i,j,k;
38     //freopen("1.in","r",stdin);
39     while(scanf("%d",&uN)!=EOF)
40     {
41         if(uN==0)   break;
42         scanf("%d%d",&vN,&k);
43         int p,q;
44         memset(g,0,sizeof(g));
45         while(k--)
46         {
47             scanf("%d%d%d",&i,&p,&q);
48             if(p>0&&q>0)    g[p][q]=1;
49         }
50         printf("%d\n",hungary());
51     }
52     return 0;
53 }