【bzoj3786】星系探索

#include<bits/stdc++.h>
#define N 100010
using namespace std;
typedef long long ll;
const int M=200500;
int n,m,a[M];
struct Edge{int u,v,next;}G[M];
int head[M],tot=0,tpos[M],rt;
inline void addedge(int u,int v){
    G[++tot].u=u;G[tot].v=v;G[tot].next=head[u];head[u]=tot;
    G[++tot].u=v;G[tot].v=u;G[tot].next=head[v];head[v]=tot;
}
int size[M],c[M][3],val[M],addv[M],fa[M],w[M],s[M],top;
ll sumv[M];
inline void pushup(int x){
    size[x]=size[c[x][0]]+size[c[x][1]]+w[x];
    sumv[x]=sumv[c[x][0]]+sumv[c[x][1]]+w[x]*val[x];
}
inline void puttag(int x,ll v){val[x]+=v;addv[x]+=v;sumv[x]+=v*size[x];}
inline void pushdown(int x){
    if(!addv[x])return ;
    if(c[x][0])puttag(c[x][0],addv[x]);
    if(c[x][1])puttag(c[x][1],addv[x]);    
    addv[x]=0;
}
inline void rotate(int x,int &k){
    int y=fa[x],z=fa[y],l,r;
    if(c[y][0]==x)l=0;else l=1;r=l^1;
    if(y==k)k=x;else{if(c[z][0]==y)c[z][0]=x;else c[z][1]=x;}
    fa[x]=z;fa[y]=x;fa[c[x][r]]=y;
    c[y][l]=c[x][r];c[x][r]=y;
    pushup(y);pushup(x);
}
inline void splay(int x,int &k){
    s[top=1]=x;for(int i=x;i!=rt;i=fa[i])s[++top]=fa[i];
       for(int i=top;i;--i)pushdown(s[i]);
       while(x!=k){
           int y=fa[x],z=fa[y];
           if(y!=k)
               if(c[z][0]==y^c[y][0]==x)rotate(x,k);
               else rotate(y,k);
           rotate(x,k);
       }
}
inline void ins(int x,int v,int ww){
    if(!rt)rt=x;else fa[x]=rt,c[rt][1]=x;
    val[x]=v;w[x]=ww;pushup(x);splay(x,rt);
}
inline int tmax(int x){while(c[x][1])x=c[x][1];return x;}
inline int tmin(int x){while(c[x][0])x=c[x][0];return x;}
inline ll query(int x){
    splay(x,rt);return sumv[c[x][0]]+1LL*w[x]*val[x];
}
inline void change(int x,int y){
    splay(x,rt);int t1=tmax(c[rt][0]);
    splay(x+N,rt);int t2=tmin(c[rt][1]);
    splay(t1,rt);splay(t2,c[t1][1]);
    int z=c[t2][0];fa[z]=c[t2][0]=0;
    splay(y,rt);int t3=tmin(c[y][1]);
    splay(t3,c[y][1]);fa[z]=t3;c[t3][0]=z;
}
inline void add(int x,int v){
    splay(x,rt);int t1=tmax(c[rt][0]);
       splay(x+N,rt);int t2=tmin(c[rt][1]);
       splay(t1,rt);splay(t2,c[t1][1]);
       puttag(c[t2][0],v);
}
void build(int u,int f){
    ins(u+1,a[u],1);
    for(int i=head[u];i;i=G[i].next){
        int v=G[i].v;if(v==f)continue;
        build(v,u);
    }
    ins(u+N+1,a[u],-1);
}
int main(){
    n=io.read();
    for(int i=2;i<=n;i++){int u=io.read();addedge(u,i);}
    for(int i=1;i<=n;i++)a[i]=io.read();
    ins(1,0,0);build(1,0);ins(N*2+1,0,0);
    m=io.read();char s[20];
    while(m--){
        scanf("%s",s);
        if(s[0]==‘Q‘){int x=read();printf("%lld\n",query(x+1));}
        if(s[0]==‘C‘){int x=read(),y=read();change(x+1,y+1);}
        if(s[0]==‘F‘){int x=read(),y=read();add(x+1,y);}
    }
    return 0;
}