[BZOJ3532] [Sdoi2014]Lis

Posted 2020-09-07 CHADLZX

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 说起这道题,我的唯一感受是:该死,TM卡常.

 这卡常卡的我不要不要的,反正我最后没卡过去.

 .....................................................愤怒的分割线..............

 这道题的主要思路是求字典序最小的最小割,做完最小割后,按照贪心原则选取,每选中一条边,那么做T->V和U->S的最大流,消除这条边的影响.

 代码感觉在什么地方死循环了,一直TLE,但并没有什么发现.

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<ctime>
#include<cmath>
#include<algorithm>
#include<queue>
#include<set>
#include<map>
#include<iomanip>
using namespace std;
#define ll long long
#define db double 
#define up(i,j,n) for(int i=j;i<=n;i++)
#define pii pair<int,int>
#define uint unsigned int
#define FILE "dealing"
#define eps 1e-4
int read(){
	int x=0,f=1,ch=getchar();
	while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=-1;ch=getchar();}
	while(ch>=‘0‘&&ch<=‘9‘){x=(x<<1)+(x<<3)+ch-‘0‘;ch=getchar();}
	return x*f;
}
template<class T>  bool cmax(T& a,T b){return a<b?a=b,true:false;}
template<class T>  bool cmin(T& a,T b){return a>b?a=b,true:false;}
const int maxn=100550,limit=50100,inf=(int)(2e9),mod=(int)1e9+7;
int n;
int a[maxn],b[maxn],c[maxn];
namespace dinic{
	struct node{
		int y,next,rev;int flow;
	}e[maxn<<1];int len,linkk[maxn];
	void insert(int x,int y,int flow){
		e[++len].y=y;
		e[len].next=linkk[x];
		linkk[x]=len;
		e[len].flow=flow;
		e[len].rev=len+1;
		e[++len].y=x;
		e[len].next=linkk[y];
		linkk[y]=len;
		e[len].flow=0;
		e[len].rev=len-1;
	}
	int S,T,SS,TT,q[maxn],d[maxn],head,tail;
	bool makelevel(){
		head=tail=0;
		up(i,0,n*2+2)d[i]=-1;
		d[S]=0;q[++tail]=S;
		while(++head<=tail){
			int x=q[head];
			for(int i=linkk[x];i;i=e[i].next)
				if(d[e[i].y]==-1&&e[i].flow)d[e[i].y]=d[x]+1,q[++tail]=e[i].y;
		}
		return d[T]!=-1;
	}
	int makeflow(int x,int flow){
		if(x==T||!flow)return flow;
		int maxflow=0,dis;
		for(int i=linkk[x];i&&maxflow<flow;i=e[i].next){
			if(e[i].flow&&d[e[i].y]==d[x]+1)
				if(dis=makeflow(e[i].y,min(e[i].flow,flow-maxflow))){
					e[i].flow-=dis;
					e[e[i].rev].flow+=dis;
					maxflow+=dis;
				}
		}
		if(!maxflow)d[x]=-1;
		return maxflow;
	}
	int dinic(){
		int ans=0,d;
		while(makelevel())
			while(d=makeflow(S,inf))
				ans+=d;
		return ans;
	}
	int f[maxn],Max;
	pii k[maxn];
	void prepare(){
		up(i,0,n*2+2)linkk[i]=f[i]=0;
		len=0;
	}
	void makeedge(){
		prepare();
		Max=0;SS=S=n*2+1,TT=T=S+1;
		up(i,1,n)insert(i*2-1,i*2,b[i]);
		up(i,1,n)up(j,0,i-1)if(a[i]>a[j])cmax(f[i],f[j]+1);
		up(i,1,n)up(j,i+1,n)if(a[j]>a[i]&&f[j]==f[i]+1)insert(i*2,j*2-1,inf);
		up(i,1,n)cmax(Max,f[i]);
		up(i,1,n){
			if(Max==f[i])insert(i*2,T,inf);
			if(f[i]==1)insert(S,i*2-1,inf);
		}
	}
	int po[maxn],cnt=0;
	void solve(){
		up(i,1,n)k[i].first=c[i],k[i].second=i;
		sort(k+1,k+n+1);cnt=0;
		int ans=dinic();
		up(i,1,n){
			int x=k[i].second;
			S=x*2-1,T=x*2;
			if(!makelevel()){
				po[++cnt]=x;
				S=TT,T=x*2;
				dinic();
				S=x*2-1,T=SS;
				dinic();
				e[x*2].flow=0;
			}
		}
		printf("%d %d\n",ans,cnt);
		sort(po+1,po+cnt+1);
		up(i,1,cnt)printf("%d%c",po[i],i==cnt?‘\n‘:‘ ‘);
	}
};
int main(){
	freopen(FILE".in","r",stdin);
	freopen(FILE".out","w",stdout);
	int T;
	scanf("%d",&T);
	while(T--){
		scanf("%d",&n);
		up(i,1,n)scanf("%d",&a[i]);
		up(i,1,n)scanf("%d",&b[i]);
		up(i,1,n)scanf("%d",&c[i]);
		dinic::makeedge();
		dinic::solve();
	}
	//cout<<clock()<<endl;
	return 0;
}