hdu 5352 匈牙利（多重匹配）

由于实在不想拆点，写了个这样的代码：

  1 #include <iostream>
  2 #include <cstring>
  3 #include <cstdio>
  4 #include <set>
  5 using namespace std;
  6 
  7 const int N = 5000;
  8 bool g[N][N];
  9 bool g2[N][N];
 10 bool visit[N];
 11 set<int> mark[N];
 12 set<int>::iterator it;
 13 int n, m, mm, k;
 14 
 15 void dfs1( int u )
 16 {
 17     visit[u] = 1;
 18     for ( int i = 1; i <= n; i++ )
 19     {
 20         if ( !visit[i] && g[u][i] )
 21         {
 22             dfs1(i);
 23         }
 24     }
 25 }
 26 
 27 int dfs2( int u )
 28 {
 29     for ( int i = mm; i >= 1; i-- )
 30     {
 31         if ( !visit[i] && g2[u][i] )
 32         {
 33             visit[i] = 1;
 34             if ( mark[i].size() < k )
 35             {
 36                 mark[i].insert(u);
 37                 return 1;
 38             }
 39             for ( it = mark[i].begin(); it != mark[i].end(); it++ )
 40             {
 41                 if ( dfs2((*it)) )
 42                 {
 43                     mark[i].erase((*it));
 44                     mark[i].insert(u);
 45                     return 1;
 46                 }
 47             }
 48         }
 49     }
 50     return 0;
 51 }
 52 
 53 void hungary()
 54 {
 55     for ( int i = 1; i <= mm; i++ )
 56     {
 57         mark[i].clear();
 58     }
 59     int res = 0;
 60     for ( int i = 1; i <= n; i++ )
 61     {
 62         memset( visit, 0, sizeof(visit) );
 63         res += dfs2(i);
 64     }
 65     printf("%d\n", res);
 66     for ( int i = 1; i <= mm; i++ )
 67     {
 68         printf("%d", mark[i].size());
 69         if ( i != mm ) putchar(' ');
 70         else putchar('\n');
 71     }
 72 }
 73 
 74 int main ()
 75 {
 76     int t;
 77     scanf("%d", &t);
 78     while ( t-- )
 79     {
 80         scanf("%d%d%d", &n, &m, &k);
 81         mm = 0;
 82         memset( g, 0, sizeof(g) );
 83         memset( g2, 0, sizeof(g2) );
 84         while ( m-- )
 85         {
 86             int op;
 87             scanf("%d", &op);
 88             if ( op == 1 )
 89             {
 90                 mm++;
 91                 int r;
 92                 scanf("%d", &r);
 93                 memset( visit, 0, sizeof(visit) );
 94                 dfs1(r);
 95                 for ( int j = 1; j <= n; j++ )
 96                 {
 97                     if ( visit[j] )
 98                     {
 99                         g2[j][mm] = 1;
100                     }
101                 }
102             }
103             else if ( op == 2 )
104             {
105                 int u, v;
106                 scanf("%d%d", &u, &v);
107                 g[u][v] = g[v][u] = 1;
108             }
109             else if ( op == 3 )
110             {
111                 int q;
112                 scanf("%d", &q);
113                 while ( q-- )
114                 {
115                     int u, v;
116                     scanf("%d%d", &u, &v);
117                     g[u][v] = g[v][u] = 0;
118                 }
119             }
120         }
121         hungary();
122     }
123     return 0;
124 }

不过很可惜，这份代码是过不去的，具体原因我还没有找到。

只好乖乖拆点了...

  1 #include <iostream>
  2 #include <cstring>
  3 #include <cstdio>
  4 using namespace std;
  5 
  6 const int N = 501;
  7 const int M = 7000;
  8 const int K = 300000;
  9 bool g[N][N];
 10 bool visit[N];
 11 int head[M];
 12 int mark[N];
 13 int ans[N];
 14 int table[N];
 15 int n, m, k, p, e, ptr;
 16 
 17 struct Edge 
 18 {
 19     int v, next;
 20 } edge[K];
 21 
 22 void addEdge( int u, int v )
 23 {
 24     edge[e].v = v;
 25     edge[e].next = head[u];
 26     head[u] = e++;
 27 }
 28 
 29 void dfs1( int u )
 30 {
 31     visit[u] = 1;
 32     table[ptr++] = u;
 33     for ( int i = 1; i <= n; i++ )
 34     {
 35         if ( !visit[i] && g[u][i] )
 36         {
 37             dfs1(i);
 38         }
 39     }
 40 }
 41 
 42 int dfs2( int u )
 43 {
 44     for ( int i = head[u]; i != -1; i = edge[i].next )
 45     {
 46         int v = edge[i].v;
 47         if ( !visit[v] )
 48         {
 49             visit[v] = 1;
 50             if ( mark[v] == -1 || dfs2(mark[v]) )
 51             {
 52                 mark[v] = u;
 53                 return 1;
 54             }
 55         }
 56     }
 57     return 0;
 58 }
 59 
 60 void hungary()
 61 {
 62     int res = 0;
 63     memset( mark, -1, sizeof(mark) );
 64     memset( ans, 0, sizeof(ans) );
 65     for ( int i = p - 1; i >= 0; i-- )
 66     {
 67         for ( int j = i * k + 1; j <= ( i + 1 ) * k; j++ )
 68         {
 69             memset( visit, 0, sizeof(visit) );
 70             if ( dfs2(j) )
 71             {
 72                 res++;
 73                 ans[i]++;
 74             }
 75         }
 76     }    
 77     printf("%d\n", res);
 78     for ( int i = 0; i < p - 1; i++ )
 79     {
 80         printf("%d ", ans[i]);
 81     }
 82     printf("%d\n", ans[p - 1]);
 83 }
 84 
 85 int main ()
 86 {
 87     int t;
 88     scanf("%d", &t);
 89     while ( t-- )
 90     {
 91         scanf("%d%d%d", &n, &m, &k);
 92         e = p = 0;
 93         memset( head, -1, sizeof(head) );
 94         memset( g, 0, sizeof(g) );
 95         while ( m-- )
 96         {
 97             int op;
 98             scanf("%d", &op);
 99             if ( op == 1 )
100             {
101                 int r;
102                 scanf("%d", &r);
103                 memset( visit, 0, sizeof(visit) );
104                 ptr = 0;
105                 dfs1(r);
106                 for ( int j = 0; j < ptr; j++ )
107                 {
108                     for ( int y = p * k + 1; y <= ( p + 1 ) * k; y++ )
109                     {
110                         addEdge( y, table[j] );
111                     }
112                 }
113                 p++;
114             }
115             else if ( op == 2 )
116             {
117                 int u, v;
118                 scanf("%d%d", &u, &v);
119                 g[u][v] = g[v][u] = 1;
120             }
121             else if ( op == 3 )
122             {
123                 int q;
124                 scanf("%d", &q);
125                 while ( q-- )
126                 {
127                     int u, v;
128                     scanf("%d%d", &u, &v);
129                     g[u][v] = g[v][u] = 0;
130                 }
131             }
132         }
133         hungary();
134     }
135     return 0;
136 }