Luogu P2146 [NOI2015]软件包管理器 树剖

卸载：把子树清空；

安装：把自己到$1$的链改为$1$

#include<cstdio>
#include<iostream>
#include<cstring>
#define R register int
#define ls (tr<<1)
#define rs (tr<<1|1)
using namespace std;
inline int g() {
    R ret=,fix=; register char ch; while(!isdigit(ch=getchar())) fix=ch=='-'?-:fix;
    do ret=ret*+(ch^); while(isdigit(ch=getchar())); return ret*fix;
} const int N=;
int n,m,cnt,num;
int vr[N<<],nxt[N<<],fir[N],sz[N],top[N],dfn[N],pre[N],d[N],son[N],sum[N<<],tg[N<<];
inline void add(int u,int v) {vr[++cnt]=v,nxt[cnt]=fir[u],fir[u]=cnt;}
inline void dfs1(int u) { sz[u]=; R mx=;
    for(R i=fir[u];i;i=nxt[i]) { R v=vr[i];
        if(!d[v]) {
            d[v]=d[u]+; dfs1(v); sz[u]+=sz[v];
            if(sz[v]>mx) son[u]=v,mx=sz[v];
        }
    }
}
inline void dfs2(int u,int tp) {
    top[u]=tp; dfn[u]=++num;
    if(son[u]) dfs2(son[u],tp);
    for(R i=fir[u];i;i=nxt[i]) { R v=vr[i];
        if(v!=pre[u]&&v!=son[u]) dfs2(v,v);
    }
}
inline void spread(int tr,int l,int r) { if(~tg[tr]) {
        R md=l+r>>;
        tg[ls]=tg[tr],sum[ls]=(md-l+)*tg[tr];
        tg[rs]=tg[tr],sum[rs]=(r-md)*tg[tr]; tg[tr]=-;
    }
}
inline void update(int tr,int l,int r,int LL,int RR,int d) {
    if(LL<=l&&r<=RR) {tg[tr]=d,sum[tr]=(r-l+)*d; return ;} spread(tr,l,r); R md=l+r>>;
    if(LL<=md) update(ls,l,md,LL,RR,d); if(RR>md) update(rs,md+,r,LL,RR,d);
    sum[tr]=sum[ls]+sum[rs];
}
inline void change(int u,int inc) {
    while(top[u]!=) {
        update(,,n,dfn[top[u]],dfn[u],inc);
        u=pre[top[u]];
    } update(,,n,,dfn[u],inc);
}
signed main() { memset(tg,0xff,sizeof(tg));
    n=g(); for(R i=,u;i<=n;++i) u=g()+,add(u,i),add(i,u),pre[i]=u;
    d[]=,dfs1(); dfs2(,); m=g();
    for(R i=,x;i<=m;++i) { register char ch; while(!isalpha(ch=getchar()));
        R tmp=sum[]; x=g()+;
        if(ch=='i') change(x,),printf("%d\n",sum[]-tmp);
        else if(ch=='u') {
            update(,,n,dfn[x],dfn[x]+sz[x]-,);
            printf("%d\n",tmp-sum[]);
        }
    }
}

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2019.07.03