rt，以下是神奇的的AC代码

#include<bits/stdc++.h>
#define re register 
#define mod 998244353
#define N 500010
#define eps (1e-10)
#define int long long
using namespace std;
int n,m,Sum;
int fa[N],son[N],top[N],seg[N],rev[N],sum[N<<2],laz[N<<2],size[N],dep[N];
vector <int> a[N];
char s[100];
template <class T> inline void read(T &x)
{
	x=0;int g=1;char ss=getchar();
	for (;ss>'9'||ss<'0';ss=getchar()) if (ss=='-') g=-1;
	for (;ss<='9'&&ss>='0';ss=getchar()) x=(x<<1)+(x<<3)+(ss^48);	
	x*=g;
} 
void spread(int k,int len)
{
	laz[k<<1]=laz[k];
	laz[k<<1|1]=laz[k];
	sum[k<<1]=laz[k]*(len-(len>>1));
	sum[k<<1|1]=laz[k]*(len>>1);
	laz[k]=-1;
}
void change(int k,int l,int r,int L,int R,int Val)
{
	if (L<=l&&R>=r)
	{
		laz[k]=Val;
		sum[k]=(r-l+1)*Val;
		return ;
	}
	if (laz[k]!=-1) spread(k,r-l+1);
	int mid=l+r>>1;
	if (L<=mid) change(k<<1,l,mid,L,R,Val);
	if (R>mid)  change(k<<1|1,mid+1,r,L,R,Val);
	sum[k]=sum[k<<1]+sum[k<<1|1]; 
}
void query(int k,int l,int r,int L,int R)
{
	if (L<=l&&R>=r)
	{
		Sum+=sum[k];
		return;
	}
	if (laz[k]!=-1) spread(k,r-l+1);
	int mid=l+r>>1;
	if (L<=mid) query(k<<1,l,mid,L,R);
	if (R>mid)  query(k<<1|1,mid+1,r,L,R);	
}
void ask(int x,int y,int Val)
{
	int fx=top[x],fy=top[y];
	while(fx!=fy)
	{
		if(dep[fx]<dep[fy]) swap(x,y),swap(fx,fy);
		if (Val==0)
		query(1,1,n,seg[fx],seg[x]);
		else
		change(1,1,n,seg[fx],seg[x],1);
		x=fa[fx];fx=top[x];
	}
	if (dep[x]>dep[y]) swap(x,y);
	if (Val==0)
	query(1,1,n,seg[x],seg[y]);
	else
	change(1,1,n,seg[x],seg[y],1);
}
void dfs1(int u,int f)
{
	size[u]=1;dep[u]=dep[f]+1;
	for (re int i=0;i<a[u].size();i++)
	{
		int v=a[u][i];
		if (i==0) son[u]=v;
		dfs1(v,u);
		size[u]+=size[v];
		if (size[v]>size[son[u]]) son[u]=v;
	}
}
void dfs2(int u,int f)
{
	if (son[u])
	{
		top[son[u]]=top[u];
		seg[son[u]]=++seg[0];
		rev[seg[0]]=son[u];
		dfs2(son[u],u);
	}
	for (re int i=0;i<a[u].size();i++)
	{
		int v=a[u][i];
		if (v==son[u]) continue;
		top[v]=v;
		seg[v]=++seg[0];
		rev[seg[0]]=v;
		dfs2(v,u);
	}
}
void build(int k,int l,int r)
{
	laz[k]=-1;
	if (l==r) return ;
	int mid=l+r>>1;
	build(k<<1,l,mid);
	build(k<<1|1,mid+1,r);
}
signed main()
{
	re int i,j,x,y,z,op;
	read(n);
	for (i=2;i<=n;i++)
	{
		read(fa[i]);
		fa[i]++;
		a[fa[i]].push_back(i);
	}
	dfs1(1,0);
	seg[0]=1;seg[1]=1;rev[1]=1;top[1]=1; 
	dfs2(1,0);
	build(1,n,n);//build(1,1,n);
	read(m);
	while(m--)
	{
		scanf("%s",s);read(x);x++;
		Sum=0;
		if (s[0]=='i')
		{
			ask(1,x,0);
			int ans=dep[x]-Sum;
			printf("%lld\n",ans);
			ask(1,x,1);
		}
		else 
		{
			query(1,1,seg[0],seg[x],seg[x]+size[x]-1);
			printf("%lld\n",Sum);
			change(1,1,seg[0],seg[x],seg[x]+size[x]-1,0);
		}
	} 
	return 0;
}

另外还有一个问题是为什么题解里都是从1开始编号（开始本蒟蒻不知道要改编号，经过一系列debug后的代码也能过），以下是从0开始编号的AC代码

#include<bits/stdc++.h>
#define re register 
#define mod 998244353
#define N 500010
#define eps (1e-10)
#define int long long
using namespace std;
int n,m,Sum,cnt;
int fa[N],son[N],top[N],seg[N],rev[N],sum[N<<2],laz[N<<2],size[N],dep[N];
vector <int> a[N];
char s[100];
template <class T> inline void read(T &x)
{
	x=0;int g=1;char ss=getchar();
	for (;ss>'9'||ss<'0';ss=getchar()) if (ss=='-') g=-1;
	for (;ss<='9'&&ss>='0';ss=getchar()) x=(x<<1)+(x<<3)+(ss^48);	
	x*=g;
} 
void spread(int k,int len)
{
	laz[k<<1]=laz[k];
	laz[k<<1|1]=laz[k];
	sum[k<<1]=laz[k]*(len-(len>>1));
	sum[k<<1|1]=laz[k]*(len>>1);
	laz[k]=-1;
}
void change(int k,int l,int r,int L,int R,int Val)
{
	if (L<=l&&R>=r)
	{
		laz[k]=Val;
		sum[k]=(r-l+1)*Val;
		return ;
	}
	if (laz[k]!=-1) spread(k,r-l+1);
	int mid=l+r>>1;
	if (L<=mid) change(k<<1,l,mid,L,R,Val);
	if (R>mid)  change(k<<1|1,mid+1,r,L,R,Val);
	sum[k]=sum[k<<1]+sum[k<<1|1]; 
}
void query(int k,int l,int r,int L,int R)
{
	if (L<=l&&R>=r)
	{
		Sum+=sum[k];
		return;
	}
	if (laz[k]!=-1) spread(k,r-l+1);
	int mid=l+r>>1;
	if (L<=mid) query(k<<1,l,mid,L,R);
	if (R>mid)  query(k<<1|1,mid+1,r,L,R);	
}
void ask(int x,int y,int Val)
{
	int fx=top[x],fy=top[y];
	while(fx!=fy)
	{
		if(dep[fx]<dep[fy]) swap(x,y),swap(fx,fy);
		if (Val==0)
		query(1,1,n,seg[fx],seg[x]);
		else
		change(1,1,n,seg[fx],seg[x],1);
		x=fa[fx];fx=top[x];
	}
	if (dep[x]>dep[y]) swap(x,y);
	if (Val==0)
	query(1,1,n,seg[x],seg[y]);
	else
	change(1,1,n,seg[x],seg[y],1);
}
void dfs1(int u,int f)
{
	size[u]=1;dep[u]=dep[f]+1;
	for (re int i=0;i<a[u].size();i++)
	{
		int v=a[u][i];
		if (i==0) son[u]=v;
		dfs1(v,u);
		size[u]+=size[v];
		if (size[v]>size[son[u]]) son[u]=v;
	}
}
void dfs2(int u,int f)
{
	if (son[u])
	{
		top[son[u]]=top[u];
		seg[son[u]]=++cnt;
		rev[cnt]=son[u];
		dfs2(son[u],u);
	}
	for (re int i=0;i<a[u].size();i++)
	{
		int v=a[u][i];
		if (v==son[u]) continue;
		top[v]=v;
		seg[v]=++cnt;
		rev[cnt]=v;
		dfs2(v,u);
	}
}
void build(int k,int l,int r)
{
	laz[k]=-1;
	if (l==r) return ;
	int mid=l+r>>1;
	build(k<<1,l,mid);
	build(k<<1|1,mid+1,r);
}
signed main()
{
	re int i,j,x,y,z,op;
	read(n);
	for (i=1;i<n;i++)
	{
		read(fa[i]);a[fa[i]].push_back(i);
	}
	dfs1(0,0);
	cnt=1;seg[0]=1;
	dfs2(0,0);
	build(1,1,n);
	read(m);
	while(m--)
	{
		scanf("%s",s);read(x);
		Sum=0;
		if (s[0]=='i')
		{
			ask(0,x,0);
			int ans=dep[x]-Sum;
			printf("%lld\n",ans);
			ask(0,x,1);
		}
		else 
		{
			query(1,1,cnt,seg[x],seg[x]+size[x]-1);
			printf("%lld\n",Sum);
			change(1,1,cnt,seg[x],seg[x]+size[x]-1,0);
		}
	} 
	return 0;
}