P2762 [网络流24题]太空飞行计划问题(最小割)

地址

最大权闭合子图裸题，不说了吧，求方案就是把s集遍历一遍。

错误记录：dfs那块忘判断残量了，11分×1.

 #include<cstdio>
 #include<iostream>
 #include<cstring>
 #include<queue>
 using namespace std;
 typedef long long ll;
 template<typename T>inline char MIN(T&A,T B){return A>B?A=B,:;}
 template<typename T>inline char MAX(T&A,T B){return A<B?A=B,:;}
 template<typename T>inline T _min(T A,T B){return A<B?A:B;}
 template<typename T>inline T _max(T A,T B){return A>B?A:B;}
 template<typename T>inline void inc(T&A,T B){A+=B;}
 inline int read(int&x){
     x=;int f=;char c;while(!isdigit(c=getchar()))if(c=='-')f=;
     while(isdigit(c))x=x*+c-'',c=getchar();if(c=='\n')return -;return f?-x:x;
 }
 const int N=+,M=+,INF=0x3f3f3f3f;
 int Head[N],cur[N],Next[M<<],v[M<<],w[M<<],dis[N],vis[N],tot=,n,m,cnt,s,t;

 inline void Addedge(int x,int y,int z){
     v[++tot]=y,Next[tot]=Head[x],Head[x]=tot,w[tot]=z;
     v[++tot]=x,Next[tot]=Head[y],Head[y]=tot,w[tot]=;
 }
 #define y v[j]
 inline int bfs(){
     queue<int> q;memset(dis,,sizeof dis),dis[s]=,q.push(s);
     for(register int i=;i<=(n+m)+;++i)cur[i]=Head[i];
     while(!q.empty()){
         int x=q.front();q.pop();
         for(register int j=Head[x];j;j=Next[j])if(w[j]&&!dis[y]){
             dis[y]=dis[x]+,q.push(y);
             if(y==t)return ;
         }
     }
     return ;
 }
 int dinic(int x,int flow){
     if(!flow||x==t)return flow;
     int rest=flow,k;
     for(register int j=cur[x];j&&rest;cur[x]=j,j=Next[j])if(w[j]&&dis[y]==dis[x]+){
         if(!(k=dinic(y,_min(rest,w[j]))))dis[y]=;
         rest-=k,w[j]-=k,w[j^]+=k;
     }
     return flow-rest;
 }
 #undef y
 int x,y,z,maxflow;ll ans;
 void dfs(int x){
     vis[x]=;for(register int j=Head[x];j;j=Next[j])if(w[j]&&!vis[v[j]])dfs(v[j]);
 }

 int main(){//freopen("P2762.in","r",stdin);//freopen("tmp.out","w",stdout);
     read(m),read(n);s=n+m+,t=s+;
     for(register int i=;i<=m;++i){
         ans+=read(z),Addedge(s,i,z);while(~read(y))Addedge(i,y+m,INF); Addedge(i,y+m,INF);
     }
     for(register int i=;i<=n;++i)read(z),Addedge(i+m,t,z);
     while(bfs())maxflow+=dinic(s,INF);//printf("%lld %d\n",ans,maxflow);
     ans-=maxflow,dfs(s);
     for(register int i=;i<=m;++i)if(vis[i])printf("%d ",i);puts("");
     for(register int i=;i<=n;++i)if(vis[i+m])printf("%d ",i);puts("");
     printf("%d\n",ans);
     return ;
 }