[Luogu 3410]拍照

题目类型：最大权值闭合子图

题目分析：

实现代码：

#include <cstdio>
#include <iostream>
#include <queue>
#include <cstring>
#define il inline
using namespace std;
const int inf=0x7fffffff;
const int maxm=210000;
int head[maxm],to[maxm*2],cap[maxm*2],net[maxm*2],deep[maxm],cnt=1;
il void add(int x,int y,int c){cnt++,to[cnt]=y,cap[cnt]=c,net[cnt]=head[x],head[x]=cnt;}
queue <int> dl;
int vis[maxm];
il bool BFS(int s,int t)
{
while(!dl.empty()) dl.pop();
memset(deep,-1,sizeof(deep));
dl.push(s),deep[s]=0;
while(!dl.empty())
{
int x=dl.front();dl.pop();
for(int i=head[x];i;i=net[i])
if(cap[i]>0&&deep[to[i]]==-1)
dl.push(to[i]),deep[to[i]]=deep[x]+1;
}
return deep[t]==-1?0:1;
}
int dfs(int now,int flow,int t)
{
if(now==t) return flow;
int w,used=0;
for(int i=head[now];i;i=net[i])
{
int v=to[i];
if(deep[v]==deep[now]+1&&cap[i])
{
w=dfs(v,min(flow-used,cap[i]),t);
cap[i]-=w;
cap[i^1]+=w;
used+=w;
if(used==flow) return flow;
}
}
if(!used) deep[now]=-1;
return used;
}
il int dinic(int s,int t)
{
int maxflow=0;
while(BFS(s,t)) maxflow+=dfs(s,inf,t);
return maxflow;
}
inline void adx(int x,int y,int cax)
{
add(x,y,cax),add(y,x,0);
}
int main()
{
int n,m;
scanf("%d%d",&m,&n);
int s=n+m+99,t=n+m+100,sum=0;

for(int i=1;i<=m;i++)
{
int c;
scanf("%d",&c);
adx(s,i+n,c),sum+=c;
int w;
while(1)
{
scanf("%d",&w);
if(!w) break;
adx(i+n,w,inf);
}
}
for(int i=1,c;i<=n;i++)
scanf("%d",&c),adx(i,t,c);
return printf("%d\n",max(sum-dinic(s,t),0))*0;
}