只有前四个操作的话就是LCT裸题了
链翻转不也是LCT的基本操作吗....
等等,翻转的是权值?
正常的翻转改的是各个点的深度,位置与权值的对应关系并没有改变
那么我们可以考虑维护两棵LCT,一棵维护形态,一棵维护位置
翻转其中一个就相当于改变了对应关系
说的不是很明白的啊....还是看看学姐的blog吧
代码如下:
#include<ctype.h>
#include<cstdio>
#define int long long
#define INF 2147483647000000l
#define N 50020
using namespace std;
typedef long long LL;
inline int read(){
int x=0,f=1;char c;
do c=getchar(),f=c=='-'?-1:f; while(!isdigit(c));
do x=(x<<3)+(x<<1)+c-'0',c=getchar(); while(isdigit(c));
return x*f;
}
inline int Max(int a,int b){return a>b?a:b;}
inline int Min(int a,int b){return a<b?a:b;}
inline int max3(int a,int b,int c){return Max(a,Max(b,c));}
inline int min3(int a,int b,int c){return Min(a,Min(b,c));}
int n,m,root,x,y,k,top;
int fir[N];
char c[13];
struct Edge{
int to,nex;
Edge(){}
Edge(int _,int __):to(_),nex(__){}
}nex[N<<1];
inline void add(int x,int y){
nex[++top]=Edge(y,fir[x]);
fir[x]=top;
}
struct Node{
Node *ch[2],*fa,*nex;
int sum,minn,maxx,addv,x,siz;
bool rev;
Node();
inline void Pushdown();
inline void Add(int);
inline void Reverse();
inline void maintain(){
minn=min3(ch[0]->minn,ch[1]->minn,x);
maxx=max3(ch[0]->maxx,ch[1]->maxx,x);
sum=ch[0]->sum+ch[1]->sum+x;
siz=ch[0]->siz+ch[1]->siz+1;
return;
}
inline int dir(){
if(fa->ch[0]==this) return 0;
if(fa->ch[1]==this) return 1;
return -1;
}
}*null,*p[N];
inline void Swap(Node *&a,Node *&b){static Node *c;c=a;a=b;b=c;}
Node::Node(){
x=addv=minn=maxx=sum=rev=0;
siz=1;
ch[0]=ch[1]=nex=fa=null;
return;
}
inline void Node::Pushdown(){
if(addv){
ch[0]->Add(addv);
ch[1]->Add(addv);
}
if(rev) ch[0]->Reverse(),ch[1]->Reverse();
if(nex!=null){
if(ch[0]!=null) ch[0]->nex=nex;
if(ch[1]!=null) ch[1]->nex=nex;
}
addv=rev=0;
}
inline void Node::Add(int k){
if(this==null) return;
addv=addv+k;sum=sum+k*siz;
x+=k;minn+=k;maxx+=k;
return;
}
inline void Node::Reverse(){
if(this==null) return;
Swap(ch[0],ch[1]);
rev=!rev;
return;
}
inline void init(){
null=new Node;
null->ch[0]=null->ch[1]=null->fa=null->nex=null;
null->sum=null->x=null->siz=null->addv=null->rev=0;
null->minn=INF;null->maxx=-INF;
return;
}
void PushUp(Node *x){
if(~x->dir()) PushUp(x->fa);
x->Pushdown();
return;
}
inline Node *K_th(Node *x,int k){
if(x==null) return x;
x->Pushdown();
if(x->ch[0]->siz+1==k)
return x;
if(k<=x->ch[0]->siz) return K_th(x->ch[0],k);
else return K_th(x->ch[1],k-x->ch[0]->siz-1);
}
inline void Rotate(Node *x,int d){
static Node *k;
static int di;
k=x->ch[d^1];
x->ch[d^1]=k->ch[d];
if(x->ch[d^1]!=null) x->ch[d^1]->fa=x;
k->ch[d]=x;
if(~(di=x->dir())) x->fa->ch[di]=k;
k->fa=x->fa;x->fa=k;
x->maintain();k->maintain();
return;
}
inline void Splay(Node *x){
static int d;
PushUp(x);
while(~(d=x->dir())){
if(x->fa->dir()==d)
Rotate(x->fa->fa,d^1);
Rotate(x->fa,d^1);
}
return;
}
inline void Splay_(Node *x,Node *&y){
Splay(x);Splay(x->nex);
y=K_th(x->nex,x->ch[0]->siz+1);
Splay(y);
return;
}
void dfs(int x,int fa){
p[x]=new Node;p[x]->nex=new Node;
p[x]->fa=p[fa];p[x]->nex->fa=p[fa]->nex;
for(int i=fir[x];i;i=nex[i].nex){
if(nex[i].to==fa) continue;
dfs(nex[i].to,x);
}
}
inline void Access(Node *x){
static Node *pre,*pre_,*x_;
pre=pre_=x_=null;
while(x!=null){
Splay_(x,x_);
x->nex=x_;
x->ch[1]->nex=x_->ch[1];
x->ch[1]=pre;x_->ch[1]=pre_;
pre_->fa=x_;
x->maintain();x_->maintain();
pre=x;pre_=x_;
x=x->fa;
}
return;
}
inline void MakeRoot(Node *x){
static Node *k;
Access(x);Splay_(x,k);
x->Reverse();k->Reverse();
return;
}
inline Node *Extract(Node *x,Node *y){
static Node *y_;
MakeRoot(x);
Access(y);Splay_(y,y_);
return y_;
}
main(){
init();
n=read();m=read();root=read();
for(register int i=1;i<n;i++){
x=read();y=read();
add(x,y);add(y,x);
}
p[0]=null;
dfs(root,0);
for(register int i=1;i<=m;i++){
scanf("%s",c+1);
x=read();y=read();
if(c[3]=='c') k=read(),Extract(p[x],p[y])->Add(k);
else if(c[3]=='m') printf("%lld\n",Extract(p[x],p[y])->sum);
else if(c[3]=='j') printf("%lld\n",Extract(p[x],p[y])->maxx);
else if(c[3]=='n') printf("%lld\n",Extract(p[x],p[y])->minn);
else Extract(p[x],p[y])->Reverse();
}
return 0;
}