学步园

#include <iostream>
#include <algorithm>
#include <cstdio>
using namespace std;
const int N=100009;
struct Edge
{
    int v,next;
}edge[N];
struct Hash
{
    int a,b;
}h[N];
struct Tree
{
    int cover,val;
}tree[N<<2];
int cur,head[N];

void dfs(int x)
{
    if(x<=0) return;
    cur++;
    h[x].a=cur;
    int e=head[x];
    while(e>0)
    {
        dfs(edge[e].v);
        e=edge[e].next;
    }
    h[x].b=cur;
}

void build(int l,int r,int id)
{
    tree[id].cover=tree[id].val=0;
    if(l<r)
    {
        int mid=(l+r)>>1;
        build(l,mid,id<<1);
        build(mid+1,r,id<<1|1);
    }
}

void pushup(int id)
{
    tree[id].val=tree[id<<1].val+tree[id<<1|1].val;
}

void pushdown(int l,int r,int id)
{
    if(tree[id].cover)
    {
        tree[id<<1].cover ^= 1;
        tree[id<<1|1].cover ^= 1;
        int mid=(l+r)>>1;
        tree[id<<1].val=mid-l+1-tree[id<<1].val;
        tree[id<<1|1].val=r-mid-tree[id<<1|1].val;
        tree[id].cover=0;
    }
}

int answer(int L,int R,int l,int r,int id)
{
    if(L<=l && r<=R) return tree[id].val;
    pushdown(l,r,id);
    int ans=0,mid=(l+r)>>1;
    if(L<=mid) ans+=answer(L,R,l,mid,id<<1);
    if(R>=mid+1) ans+=answer(L,R,mid+1,r,id<<1|1);
    return ans;
}

void insert(int L,int R,int l,int r,int id)
{
    if(L<=l && r<=R)
    {
        tree[id].cover^=1;
        tree[id].val=r-l+1-tree[id].val;
        return;
    }
    pushdown(l,r,id);
    int mid=(l+r)>>1;
    if(L<=mid) insert(L,R,l,mid,id<<1);
    if(R>=mid+1) insert(L,R,mid+1,r,id<<1|1);
    pushup(id);
}

int main()
{
    //freopen("in.txt","r",stdin);
    int n,m,i,j,k,e;
    ios::sync_with_stdio(false);
    while(scanf("%d %d",&n,&m)==2)//cin>>n>>m)
    {
        for(i=1;i<=n;i++)
        {
            head[i]=0;
            edge[i].next=0;
        }
        int en=1;
        for(i=2;i<=n;i++)
        {
            scanf("%d",&k);//cin>>k;
            edge[en].v=i;
            edge[en].next=head[k];
            head[k]=en++;
        }
        cur=0;
        dfs(1);
        build(1,n,1);
        char o;
        while(m--)
        {
            scanf("%*c %c %d",&o,&k);//cin>>o>>k;
            if(o=='o') insert(h[k].a,h[k].b,1,n,1);
            else printf("%d\n",answer(h[k].a,h[k].b,1,n,1));//cout<<answer(h[k].a,h[k].b,root,0)<<endl;
            //for(i=1;i<=n;i++) cout<<h[i].a<<" "<<h[i].b<<endl;
        }
        puts("");
    }
    return 0;
}