bzoj4196[Noi2015]软件包管理器

Posted 2020-07-01 YJY_

裸的树链剖分。

对于安装 查询和维护到根路径

对于卸载 查询和维护子树信息

 

一开始线段树add[]标记要全赋值为-1

 

#include<algorithm>

#include<iostream>

#include<cstdlib>

#include<cstring>

#include<cstdio>

#include<cmath>

using namespace std;

  

typedef long long LL;

  

#define N 200010

  

int id;

int fa[N],siz[N],top[N],son[N];

int pos[N],r[N];

LL sum[N<<2],add[N<<2];

  

struct Node

{

    int to,next;

}e[N];

int head[N];

int cnt;

 

int a;

 

char s;

 

int n,q;

 

int read()

{

    int x=0,f=1;char ch=getchar();

    while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=-1;ch=getchar();}

    while(ch>=‘0‘&&ch<=‘9‘){x=x*10+ch-‘0‘;ch=getchar();}

    return x*f;

}

 

void link(int x,int y)

{

    e[++cnt]=(Node){y,head[x]};

    head[x]=cnt;

}

  

void dfs(int x)

{

    siz[x]=1;

    for (int i=head[x],mx=0;i;i=e[i].next)

        if (e[i].to!=fa[x])

        {

            fa[e[i].to]=x;

            dfs(e[i].to);

            siz[x]+=siz[e[i].to];

            if (siz[e[i].to]>mx)

                mx=siz[e[i].to],son[x]=e[i].to;

        }

}

  

void dfs2(int x,int cha)

{

    top[x]=cha;

    pos[x]=++id;

    if (son[x])

        dfs2(son[x],cha);

    for (int i=head[x];i;i=e[i].next)

        if(e[i].to!=fa[x] && e[i].to!=son[x])

            dfs2(e[i].to,e[i].to);

    r[x]=id;

}

 

void pushup(int now)

{

    sum[now]=sum[now<<1]+sum[now<<1|1];

}

 

void pushdown(int nowl,int nowr,int now,int mid)

{

    if (add[now]!=-1)

    {

        LL t=add[now];

        add[now]=-1;

        add[now<<1]=t;

        add[now<<1|1]=t;

        sum[now<<1]=t*(mid-nowl+1);

        sum[now<<1|1]=t*(nowr-mid);

    }

}

  

void update(int nowl,int nowr,int now,int s,int t,LL d)

{

    if (nowl>=s && nowr<=t)

    {

        add[now]=d;

        sum[now]=(nowr-nowl+1)*d;

        return ;

    }

    int mid=(nowl+nowr)>>1;

    pushdown(nowl,nowr,now,mid);

    if (s<=mid)

        update(nowl,mid,now<<1,s,t,d);

    if (t>mid)

        update(mid+1,nowr,now<<1|1,s,t,d);

    pushup(now);

}

  

int query(int nowl,int nowr,int now,int s,int t)

{

    if (nowl>=s && nowr<=t)

        return sum[now];

    int mid=(nowl+nowr)>>1;

    int ans=0;

    pushdown(nowl,nowr,now,mid);

    if (s<=mid)

        ans+=query(nowl,mid,now<<1,s,t);

    if (t>mid)

        ans+=query(mid+1,nowr,now<<1|1,s,t);

    return ans;

}

 

int work1(int x)

{

    int ans,res=0;

    while (x)

    {

        ans=query(1,n,1,pos[top[x]],pos[x]);

        res+=pos[x]-pos[top[x]]+1-ans; 

        update(1,n,1,pos[top[x]],pos[x],1); 

        if (ans)

            break;

        x=fa[top[x]];

    }

    return res;

}

 

int work2(int x) 

{ 

    int res;

    res=query(1,n,1,pos[x],r[x]); 

    update(1,n,1,pos[x],r[x],0); 

    return res; 

}

 

int main()

{  

     n=read();

    for (int i=1;i<n;i++)

    {

        a=read();

        link(a+1,i+1);

    }

    dfs(1);

    dfs2(1,1);

    memset(add,-1,sizeof(add));

    q=read();

    while (q--)

    {

        scanf("%c",&s);

        a=read();

        if (s==‘i‘)

            printf("%d\n",work1(a+1));

        else

            printf("%d\n",work2(a+1));

    }

    return 0;

}