[BZOJ4530][Bjoi2014][LCT维护子树信息]大融合

#include <cstdio>
#include <iostream>
#include <algorithm>
#define N 100010

using namespace std;

int n,m,x,y,tp,f
,tot
,G
;
char op;

struct lef{
lef *fa,*ch[2];
int sz,isz,rev;
}pr
,*A
,*sta
;

struct edge{
int t,nx;
}E
;

inline void reaD(int &x){
char Ch=getchar();x=0;
for(;Ch>'9'||Ch<'0';Ch=getchar());
for(;Ch>='0'&&Ch<='9';x=x*10+Ch-'0',Ch=getchar());
}

int fifa(int x){return f[x]==x?x:f[x]=fifa(f[x]);}

inline int isl(lef *x){return x->fa&&x->fa->ch[1]==x;}
inline int isr(lef *x){return !x->fa||(x->fa->ch[0]!=x&&x->fa->ch[1]!=x);}

inline void updat(lef *x){
if(!x) return; x->sz=x->isz+1;
if(x->ch[0]) x->sz+=x->ch[0]->sz;
if(x->ch[1]) x->sz+=x->ch[1]->sz;
}

inline void pushdn(lef *x){
if(!(x&&x->rev)) return;
swap(x->ch[0],x->ch[1]);
if(x->ch[0]) x->ch[0]->rev^=1;
if(x->ch[1]) x->ch[1]->rev^=1;
x->rev=0;
}

inline void rot(lef *x){
lef *y=x->fa,*z=y->fa; int lor=isl(x);
if(!isr(y)) z->ch[z->ch[1]==y]=x; x->fa=z;
if(y->ch[lor]=x->ch[lor^1]) y->ch[lor]->fa=y;
(x->ch[lor^1]=y)->fa=x; updat(y); updat(x);
}

inline void splay(lef *x){
sta[tp=1]=x;
for(lef *i=x;!isr(i);i=i->fa) sta[++tp]=i->fa;
for(;tp;--tp) pushdn(sta[tp]);
for(;!isr(x);rot(x)) if(!isr(x->fa)) rot(isl(x)^isl(x->fa)?x:x->fa);
}

inline void access(lef *x){
lef *t=0;
for(;x;x=x->fa){
splay(x);
if(x->ch[1]) x->isz+=x->ch[1]->sz;
if(t) x->isz-=t->sz;
x->ch[1]=t;
t=x;
updat(x);
}
}

inline void reverse(lef *x){
access(x); splay(x); x->rev^=1;
}

inline void link(lef *x,lef *y){
reverse(y);
reverse(x);
x->fa=y;
y->isz+=x->sz;
updat(y);
access(x);
}

int main(){
freopen("1.in","r",stdin);
freopen("1.out","w",stdout);
reaD(n);reaD(m);
for(int i=1;i<=n;i++) A[i]=&pr[i],A[i]->sz=1,tot[i]=1,f[i]=i;
for(int i=1;i<=m;i++){
while((op=getchar())!='A'&&op!='Q');
if(op=='A'){
reaD(x); reaD(y);
tot[fifa(y)]+=tot[fifa(x)];
f[fifa(x)]=fifa(y);
link(A[x],A[y]);
}
else{
reaD(x);reaD(y);
reverse(A[x]);
access(A[y]);
splay(A[x]);
printf("%d\n",(A[y]->sz)*(A[x]->sz-A[y]->sz));
}
}
}