Code:
#include<bits/stdc++.h>
#include <unordered_map>
using namespace std;
#define rg register
#define O2 __attribute__((optimize("-O2")))
char *p1,*p2,buf[100000];
#define nc() (p1==p2&&(p2=(p1=buf)+fread(buf,1,100000,stdin),p1==p2)?EOF:*p1++)
int rd() {int x=0; char c=nc(); while(c<48) c=nc(); while(c>47) x=(((x<<2)+x)<<1)+(c^48),c=nc(); return x;}
const int maxn=500003;
const int inf=10000000;
void setIO(string s) {
string in=s+".in";
freopen(in.c_str(),"r",stdin);
freopen("tt.out","w",stdout);
}
struct Splay {
#define lson ch[x][0]
#define rson ch[x][1]
int cnt;
int ch[maxn][2],siz[maxn],f[maxn],mn[maxn],mx[maxn],pos[maxn];
O2 inline void init() {
cnt=0,mx[0]=-inf,mn[0]=inf;
}
O2 inline int get(int x) {
return ch[f[x]][1]==x;
}
O2 inline void pushup(int x) {
siz[x]=siz[lson]+siz[rson]+1;
mx[x]=mn[x]=pos[x];
mx[x]=max(mx[x],mx[rson]);
mn[x]=min(mn[x],mn[lson]);
}
O2 inline void rotate(int x) {
int old=f[x],fold=f[old],which=get(x);
ch[old][which]=ch[x][which^1],f[ch[old][which]]=old;
ch[x][which^1]=old,f[old]=x,f[x]=fold;
if(fold) ch[fold][ch[fold][1]==old]=x;
pushup(old), pushup(x);
}
O2 inline void splay(int x,int &tar) {
int u=f[tar],fa;
for(;(fa=f[x])^u;rotate(x))
if(f[fa]^u)
rotate(get(fa)==get(x)?fa:x);
tar=x;
}
O2 void insert(int &x,int p,int ff) {
if(!x) {
x=++cnt,f[x]=ff,pos[x]=p;
pushup(x);
return;
}
insert(ch[x][p>pos[x]],p,x), pushup(x);
}
O2 int query(int x,int l,int r) {
if(!x||mx[x]<l||mn[x]>r) return 0;
if(mn[x]>=l&&mx[x]<=r) return siz[x];
int re=0;
if(pos[x]>=l&&pos[x]<=r) ++re;
return re+query(lson,l,r)+query(rson,l,r);
}
#undef lson
#undef rson
}tr;
struct Graph {
int edges;
int hd[maxn],to[maxn],nex[maxn];
O2 inline void addedge(int u,int v) {
nex[++edges]=hd[u],hd[u]=edges,to[edges]=v;
}
}G,V;
int oo[maxn];
vector<int>mm[maxn<<1];
vector<int>cir[maxn];
unordered_map<int, vector<int> >ins[maxn];
int n,m,id,tim;
int idx[maxn],dep[maxn],dfn[maxn],st[maxn],ed[maxn],top[maxn],dis[maxn];
unordered_map<int,int>rt[maxn];
unordered_map<int,int>bu[maxn];
namespace prepare {
int du[maxn];
queue<int>Q;
O2 void dfs(int u) {
cir[idx[u]].push_back(u);
for(rg int i=V.hd[u];i;i=V.nex[i])
{
int v=V.to[i];
if(du[v]&&!idx[v]) {
idx[v]=idx[u];
dfs(v);
break;
}
}
}
O2 inline void work() {
for(rg int i=1;i<=V.edges;++i) ++du[V.to[i]];
for(rg int i=1;i<=n;++i) if(!du[i]) Q.push(i);
while(!Q.empty()) {
int u=Q.front(); Q.pop();
for(rg int i=V.hd[u];i;i=V.nex[i]) {
int v=V.to[i];
--du[v];
if(!du[v]) Q.push(v);
}
}
for(rg int i=1;i<=n;++i) {
if(!du[i]) continue;
if(!idx[i]) idx[i]=++id, dfs(i);
}
}
};
O2 void dfs(int u,int ff) {
dep[u]=dep[ff]+1,st[u]=++tim,dfn[tim]=u;
for(rg int i=G.hd[u];i;i=G.nex[i]) {
int v=G.to[i];
if(v==ff||idx[v]) continue;
top[v]=top[u],dfs(v,u);
}
ed[u]=tim;
}
O2 int main() {
// setIO("input");
n=rd();
memset(oo, -1, sizeof(oo));
for(rg int i=1;i<=n;++i) {
int x=rd();
V.addedge(i,x); // 基环树
G.addedge(x,i); // 建树
}
prepare::work(), tr.init();
for(rg int i=1;i<=id;++i)
for(rg int j=0;j<cir[i].size();++j) {
top[cir[i][j]]=cir[i][j],dep[0]=-1,dfs(cir[i][j], 0);
dis[cir[i][j]]=j;
}
m=rd();
int lastans=0;
for(rg int i=0;i<m;++i) {
int b,cur,cur_id,cur_siz;
b=rd(), b^=lastans, lastans=0;
cur_id=idx[top[b]];
cur_siz=cir[cur_id].size();
int x1 = (dis[top[b]] - (i%cur_siz) + cur_siz) % cur_siz;
int x2 = dep[b]%cur_siz;
int tmp = (x1 - x2 + cur_siz) % cur_siz;
ins[cur_id][i+dep[b]].push_back(tmp), mm[i+dep[b]].push_back(cur_id);
for(rg int o=0;o<mm[i].size();++o) {
int uu=mm[i][o];
if(oo[uu]!=i) {
oo[uu]=i;
for(rg int j=0;j<ins[uu][i].size();++j) bu[uu][ins[uu][i][j]]+=1;
}
}
if(idx[b]) lastans+=bu[cur_id][(dis[b]-(i%cur_siz)+cur_siz)%cur_siz];
else {
cur=dep[b]+i;
tr.insert(rt[cur_id][cur], st[b], 0) , tr.splay(tr.cnt, rt[cur_id][cur]);
int a=tr.query(rt[cur_id][cur],st[b],ed[b]);
lastans+=a;
}
printf("%d\n",lastans);
}
return 0;
}