[动态树 LCT] BZOJ 2157 旅游

动态树裸题

把边建成一个点就好了

取反，打个标记

#include<cstdio>
#include<cstdlib>
#include<algorithm>
#include<cstring>
using namespace std;

inline char nc()
{
	static char buf[100000],*p1=buf,*p2=buf;
	if (p1==p2) { p2=(p1=buf)+fread(buf,1,100000,stdin); if (p1==p2) return EOF; }
	return *p1++;
}

inline void read(int &x)
{
	char c=nc(),b=1;
	for (;!(c>='0' && c<='9');c=nc()) if (c=='-') b=-1;
	for (x=0;c>='0' && c<='9';x=x*10+c-'0',c=nc()); x*=b;
}

inline void read(char *s)
{
	char c=nc(); int len=0;
	for (;!(c>='a' && c<='z' || c>='A' && c<='Z');c=nc());
	for (;c>='a' && c<='z' || c>='A' && c<='Z';s[++len]=c,c=nc()); s[++len]=0; 
}

int n;

struct Splay{
	struct node{
		int size,idx,rev,fbs;
		int val,maxv,minv;
		int sum,minimum,maximum;
		node *p,*ch[2],*fat;
		inline void setc(node *c,int d) { ch[d]=c; c->p=this; }
		inline bool dir() { return p->ch[1]==this; }
		inline void change(){
			fbs^=1;
			swap(minimum,maximum); minimum=-minimum; maximum=-maximum; sum=-sum;
			if (idx>n)
				val=-val,minv=-minv,maxv=-maxv;
		}
		inline void update() {
			size=ch[0]->size+ch[1]->size+1;
			sum=ch[0]->sum+ch[1]->sum+val; 
			minimum=min(minv,min(ch[0]->minimum,ch[1]->minimum));
			maximum=max(maxv,max(ch[0]->maximum,ch[1]->maximum));
		}
		inline void reverse() { rev^=1; swap(ch[0],ch[1]); }
		inline void pushdown(node *null){
			if (rev){
				if (ch[0]!=null) ch[0]->reverse();
				if (ch[1]!=null) ch[1]->reverse();
				rev=0;
			}
			if (fbs)
			{
				if (ch[0]!=null) ch[0]->change();
				if (ch[1]!=null) ch[1]->change();
				fbs=0;
			}
		}
	}*null,Mem[60005];
	Splay() { null=Mem; null->p=null->ch[0]=null->ch[1]=null->fat=null; null->sum=0; null->size=0; null->maximum=-1<<30; null->minimum=1<<30; }
	inline void rot(node *x){
		if (x==null || x->p==null) return ;
		bool d=x->dir(); node *p=x->p;
		if (p->p!=null) p->p->setc(x,p->dir()); else x->p=null;
		p->setc(x->ch[d^1],d); x->setc(p,d^1); p->update(); x->update(); swap(x->fat,p->fat);
	}
	inline void splay(node *x){
		static node *sta[60005];
		int pnt=0; node *y=x;
		while (y!=null) sta[++pnt]=y,y=y->p;
		for (int i=pnt;i;i--) sta[i]->pushdown(null);
		while (x->p!=null)
			if (x->p->p==null)
				rot(x);
			else
				x->dir()==x->p->dir()?(rot(x->p),rot(x)):(rot(x),rot(x));
	}
	inline node *Access(node *x){
		node *y=null;
		while (x!=null)
		{
			splay(x);
			x->ch[1]->p=null; x->ch[1]->fat=x;
			x->setc(y,1); y->fat=null;
			x->update();
			y=x; x=x->fat;
		}
		return y;
	}
	inline void Link(node *x,node *y){
		if (Jud(x,y)) return;
		Access(x)->reverse();
		splay(x);
		x->fat=y;
		Access(x);
	}
	inline void Cut(node *x){
		Access(x);
		splay(x);
		x->ch[0]->p=null; x->ch[0]=null;
		x->fat=null; x->update();
	}
	inline void Cut(node *x,node *y){
		Access(x)->reverse();
		Cut(y);
	}
	inline node *Root(node *x){
		Access(x);
		splay(x);
		node *y=x;
		while (y->ch[0]!=null) y=y->ch[0];
		return y;
	}
	inline bool Jud(node *x,node *y){
		return Root(x)==Root(y);
	}
	inline void Change(node *x,node *y){
		Access(x)->reverse();
		Access(y)->change();
	}
	inline void Change(node *x,int r){
		Access(x);
		splay(x);
		x->val=x->maxv=x->minv=r; x->update();
	}
	inline int Sum(node *x,node *y){
		Access(x)->reverse();
		return Access(y)->sum;
	}
	inline int Max(node *x,node *y){
		Access(x)->reverse();
		return Access(y)->maximum;
	}
	inline int Min(node *x,node *y){
		Access(x)->reverse();
		return Access(y)->minimum;
	}
}LCT;

Splay::node *pos[60005];

inline void Init(int n){
	for (int i=1;i<2*n;i++){
		pos[i]=LCT.Mem+i; 
		pos[i]->p=pos[i]->ch[0]=pos[i]->ch[1]=pos[i]->fat=LCT.null; 
		pos[i]->val=0; pos[i]->maxv=-1<<30; pos[i]->minv=1<<30;
		pos[i]->maximum=-1<<30; pos[i]->minimum=1<<30; pos[i]->sum=0;
		pos[i]->idx=i; pos[i]->size=1;
	}
}

int main()
{
	int u,v,w,Q;
	char order[15]={0};
	freopen("t.in","r",stdin);
	freopen("t.out","w",stdout);
	read(n); Init(n);
	for (int i=1;i<n;i++) 
	{
		read(u); read(v); read(w);
		pos[n+i]->val=pos[n+i]->maxv=pos[n+i]->minv=w;
		LCT.Link(pos[i+n],pos[++u]); LCT.Link(pos[i+n],pos[++v]);
	}
	read(Q);
	while (Q--)
	{
		read(order); read(u); read(v);
		if (!strcmp(order+1,"MAX"))
		{
			printf("%d\n",LCT.Max(pos[++u],pos[++v]));
		}
		else if (!strcmp(order+1,"MIN"))
		{
			printf("%d\n",LCT.Min(pos[++u],pos[++v]));
		}
		else if (!strcmp(order+1,"SUM"))
		{
			printf("%d\n",LCT.Sum(pos[++u],pos[++v]));
		}
		else if (!strcmp(order+1,"C"))
		{
			LCT.Change(pos[u+n],v);
		}
		else if (!strcmp(order+1,"N"))
		{
			LCT.Change(pos[++u],pos[++v]);
		}
	}
	return 0;
}