「SCOI2014」方伯伯的 OJ 解题报告

「SCOI2014」方伯伯的 OJ

和列队有点像，平衡树点分裂维护即可

但是需要额外用个set之类的对编号查找点的位置

插入完了后记得splay，删除时注意特判好多东西

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Code:

#include <cstdio>
#include <cctype>
#include <set>
const int N=2e5+10;
template <class T>
void inline read(T &x)
{
	x=0;char c=getchar();
	while(!isdigit(c)) c=getchar();
	while(isdigit(c)) x=x*10+c-'0',c=getchar();
}
#define ls ch[now][0]
#define rs ch[now][1]
#define fa par[now]
int siz[N],ch[N][2],L[N],R[N],par[N],tot,root;
void connect(int f,int now,int typ){ch[fa=f][typ]=now;}
int identity(int now){return ch[fa][1]==now;}
void updata(int now){siz[now]=siz[ls]+siz[rs]+R[now]+1-L[now];}
void Rotate(int now)
{
	int p=fa,typ=identity(now);
	connect(p,ch[now][typ^1],typ);
	connect(par[p],now,identity(p));
	connect(now,p,typ^1);
	updata(p),updata(now);
}
void splay(int now,int to)
{
	to=par[to];
	if(!to) root=now;
	for(;fa!=to;Rotate(now))
		if(par[fa]!=to)
			Rotate(identity(now)^identity(fa)?now:fa);
}
struct yuucute
{
	int x,id;
	yuucute(){}
	yuucute(int X,int Id){x=X,id=Id;}
	bool friend operator <(yuucute a,yuucute b){return a.x<b.x;}
	bool friend operator ==(yuucute a,yuucute b){return a.x==b.x;}
};
std::set <yuucute> s;
std::set <yuucute>::iterator it;
#define yuulovely 1
int New(int l,int r)
{
    siz[++tot]=r+1-l,L[tot]=l,R[tot]=r;
    return tot;
}
int getnum(int x)
{
	it=--s.upper_bound(yuucute(x,yuulovely));
	return it->id;
}
void split(int now,int x)
{
    if(L[now]==R[now]) return;
	s.erase(yuucute(L[now],yuulovely));
	s.insert(yuucute(x,now));
	int lson=ls,rson=rs;
	if(L[now]<x)
	{
		int lp=New(L[now],x-1);
		s.insert(yuucute(L[now],lp));
		connect(now,lp,0);
		connect(lp,lson,0);
		updata(lp);
	}
	if(x<R[now])
	{
		int rp=New(x+1,R[now]);
		s.insert(yuucute(x+1,rp));
		connect(now,rp,1);
		connect(rp,rson,1);
		updata(rp);
	}
	L[now]=R[now]=x;
}
void insl(int now,int ins)
{
	++siz[now];
	if(ls) insl(ls,ins);
	else connect(now,ins,0);
}
void insr(int now,int ins)
{
	++siz[now];
	if(rs) insr(rs,ins);
	else connect(now,ins,1);
}
int getlef(int now)
{
	if(ls) return getlef(ls);
	return now;
}
void erase(int now)
{
	if(!rs) {par[root=ls]=0,ls=0,updata(now);return;}
	splay(root=getlef(rs),rs);
	connect(root,ls,0);
	updata(root),par[root]=0;
	ls=rs=0,updata(now);
}
int getrank(int now,int &x)
{
	if(siz[ls]>=x) return getrank(ls,x);
	x-=siz[ls];
	if(x<=R[now]-L[now]+1) return now;
	x-=R[now]-L[now]+1;
	return getrank(rs,x);
}
int main()
{
    freopen("data.in","r",stdin);
    freopen("data.out","w",stdout);
	int n,m;
	read(n),read(m);
	root=New(1,n);
	s.insert(yuucute(1,root));
	int op,x,y,las=0;
	for(int i=1;i<=m;i++)
	{
		read(op),read(x);
		x-=las;
		if(op==1)
		{
			read(y),y-=las;
			int now=getnum(x);
			splay(now,root);
			printf("%d\n",las=siz[ls]+x+1-L[now]);
			split(now,x);
			L[now]=R[now]=y;
			s.erase(yuucute(x,yuulovely));
			s.insert(yuucute(y,now));
		}
		else if(op==2)
		{
			int now=getnum(x);
			splay(now,root);
			printf("%d\n",las=siz[ls]+x+1-L[now]);
			split(now,x);
			erase(now);
			insl(root,now);
			splay(now,root);
		}
		else if(op==3)
		{
			int now=getnum(x);
			splay(now,root);
			printf("%d\n",las=siz[ls]+x+1-L[now]);
			split(now,x);
			erase(now);
			insr(root,now);
			splay(now,root);
		}
		else
		{
			int now=getrank(root,x);
			printf("%d\n",las=x+L[now]-1);
			splay(now,root);
		}
	}
	return 0;
}

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2019.2.23