[CTSC1999]家园 分层图网络流_并查集

Code:

#include<cstdio>
#include<vector>
#include<algorithm>
#include<queue>
#include<cstring>
using namespace std;
const int maxn=100;
const int INF=1000000;
# define  pb push_back
int p[maxn],B[50],A[maxn][50];
int s,t;
int find(int x){
	if(p[x]==x)return x;
	return p[x]=find(p[x]);
}
struct loop{
	int to,cap,mod,start;
	loop(int to,int cap,int mod,int start):to(to),cap(cap),mod(mod),start(start){}
};
vector<loop>V[maxn];
struct Edge{
	int from,to,cap;
	Edge(int u,int v,int c):from(u),to(v),cap(c) {}
};
struct Dicnic{
   vector<Edge>edges;
   vector<int>G[maxn];
   int d[maxn],vis[maxn],cur[maxn];
   queue<int>Q;
   int ans=0;
   void addedge(int u,int v,int c){
	edges.pb(Edge(u,v,c));               //正向弧
	edges.pb(Edge(v,u,0));               //反向弧
	int m=edges.size();
	G[u].pb(m-2);
	G[v].pb(m-1);
   }
   int BFS()
   {
	memset(vis,0,sizeof(vis));
	d[s]=0,vis[s]=1;Q.push(s);
	while(!Q.empty()){
		int u=Q.front();Q.pop();
		int sz=G[u].size();
		for(int i=0;i<sz;++i){
			Edge e=edges[G[u][i]];
			if(!vis[e.to]&&e.cap>0){
				d[e.to]=d[u]+1,vis[e.to]=1;
				Q.push(e.to);
			}
		}
	}
	return vis[t];
   }
   int dfs(int x,int a){
	   if(x==t)return a;
	   int sz=G[x].size();
	   int f,flow=0;
	   for(int i=cur[x];i<sz;++i){
		Edge e=edges[G[x][i]];
		cur[x]=i;
		if(d[e.to]==d[x]+1&&e.cap>0){
			f=dfs(e.to,min(a,e.cap));
			if(f)
			{
				int u=G[x][i];
				a-=f;
				edges[u].cap-=f;
				edges[u^1].cap+=f;
				flow+=f;
				if(a==0)break;
			}
		}
	   }
	   return flow;
   }
   int maxflow(){
	while(BFS()){
	  memset(cur,0,sizeof(cur));
	  ans+=dfs(s,INF);
	}
	return ans;
   }
}op;
int main()
{
	int N,M,K;
	scanf("%d%d%d",&N,&M,&K);
	for(int i=0;i<=N+1;++i)A[0][i]=i;
	for(int i=1;i<=100;++i)
		for(int j=0;j<=N+1;++j)A[i][j]=A[i-1][j]+N+2;
	for(int i=0;i<100;++i)p[i]=i;                                                        //init();
	for(int i=1;i<=M;++i)
	{
		int a,b,pre;
		scanf("%d%d",&a,&b);
		for(int j=0;j<b;++j){int mm;scanf("%d",&mm);if(mm==-1)mm=N+1;B[j]=mm;}
		for(int j=0;j<b;++j){
			int u=B[j];
			if(j>0){int x=find(u);int y=find(pre);if(x!=y)p[x]=y;}
			pre=u;
			int nex=(j+1)%b;
			V[u].push_back(loop(B[nex],a,b,j));
		}
	}
	int aa=find(0);
	int bb=find(N+1);
	if(aa!=bb){printf("0");return 0;}
	s=4001,t=4002;
	op.addedge(s,0,K);
	int ans;
	for(ans=0;;++ans){
		for(int u=0;u<=N+1;++u){
			int sz=V[u].size();
			for(int i=0;i<sz;++i){
				loop lp=V[u][i];
				if(ans>=lp.start&&((ans-lp.start)%lp.mod==0))
					op.addedge(A[ans][u],A[ans+1][lp.to],lp.cap);
			}
			if(ans>0)op.addedge(A[ans-1][u],A[ans][u],INF);
		}
		op.addedge(A[ans][N+1],t,INF);
		int yy=op.maxflow();
		if(yy==K)break;
	}
	printf("%d",ans);
	return 0;
}