hdu 1068 Girls and Boys (最大独立集)

 1 #include <map>
 2 #include <queue>
 3 #include <cmath>
 4 #include <vector>
 5 #include <string>
 6 #include <cstdio>
 7 #include <cstring>
 8 #include <climits>
 9 #include <iostream>
10 #include <algorithm>
11 #define INF 0xffffff
12 using namespace std;
13 const int my_max = 1005;
14 
15 int n, m, a, b, my_G[my_max][my_max], my_book[my_max], my_right[my_max];
16 
17 bool my_dfs(int x)
18 {
19     for (int i = 0; i < n; ++ i)
20     {
21         if (my_G[x][i] && !my_book[i])
22         {
23             my_book[i] = 1;
24             if (!my_right[i] || my_dfs(my_right[i]))
25             {
26                 my_right[i] = x;
27                 return true;
28             }
29         }
30     }
31     return false;
32 }
33 
34 int my_hungarian()
35 {
36     int my_cnt = 0;
37     for (int i = 0; i < n; ++ i)
38     {
39         memset (my_book, 0, sizeof(my_book));
40         if (my_dfs(i))
41             ++ my_cnt;
42     }
43     return my_cnt / 2;
44 }
45 
46 int main()
47 {
48     while (~scanf("%d", &n))
49     {
50         memset(my_right, 0, sizeof(my_right));
51         memset(my_G, 0, sizeof(my_G));
52         for (int i = 0; i < n; ++ i)
53         {
54             scanf("%d: (%d)", &a, &m);
55             while (m --)
56             {
57                 scanf("%d", &b);
58                 my_G[a][b] = 1;
59             }
60         }
61 
62         printf("%d\n", n - my_hungarian());
63     }
64     return 0;
65 }