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| #include<iostream>
#include<cstdio>
#include<vector>
using namespace std;
long long read()
{
long long x=0,f=1; char c=getchar();
while(!isdigit(c)){if(c=='-') f=-1;c=getchar();}
while(isdigit(c)){x=x*10+c-'0';c=getchar();}
return x*f;
}
const int N=100000+1000;
const int M=30*N;
int n,r,a[N];
vector <int> e[N];
struct SegmentTree
{
static const int inf=0x3f3f3f3f;
#define mid ((now_l+now_r)>>1)
int MIN[M],son[M][2],cnt;
inline void update(int now)
{
MIN[now]=min(MIN[son[now][0]],MIN[son[now][1]]);
}
void Build(int now,int now_l,int now_r)
{
if(now_l==now_r)
{
MIN[now]=inf;
return;
}
Build(son[now][0]=++cnt,now_l,mid);
Build(son[now][1]=++cnt,mid+1,now_r);
update(now);
}
void Change(int x,int num,int now,int pre,int now_l,int now_r)
{
if(now_l==now_r)
{
MIN[now]=num;
return;
}
if(x<=mid) son[now][1]=son[pre][1],Change(x,num,son[now][0]=++cnt,son[pre][0],now_l,mid);
else son[now][0]=son[pre][0],Change(x,num,son[now][1]=++cnt,son[pre][1],mid+1,now_r);
update(now);
}
int Query(int L,int R,int now,int now_l,int now_r)
{
if(now_l>=L and now_r<=R)
return MIN[now];
int ans=inf;
if(L<=mid) ans=min(ans,Query(L,R,son[now][0],now_l,mid));
if(R>mid) ans=min(ans,Query(L,R,son[now][1],mid+1,now_r));
return ans;
}
void Print(int now,int now_l,int now_r)
{
cerr<<"no."<<now<<" now_l&r:"<<now_l<<" "<<now_r<<" sonl&r"<<son[now][0]<<" "<<son[now][1]<<" MIN:"<<MIN[now]<<endl;
if(now_l!=now_r)
{
Print(son[now][0],now_l,mid);
Print(son[now][1],mid+1,now_r);
}
}
#undef mid
}sgt;
int dfn[N],depth[N],dfn_to,size[N],depth_MAX;
void dfs(int now)
{
depth_MAX=max(depth_MAX,depth[now]);
dfn[now]=++dfn_to;
size[now]=1;
for(int i=0;i<int(e[now].size());i++)
if(dfn[e[now][i]]==0)
{
depth[e[now][i]]=depth[now]+1;
dfs(e[now][i]);
size[now]+=size[e[now][i]];
}
}
int dl[N],front,tail,root[N];
void bfs()
{
dl[tail++]=r;
int depth_now=0;
while(tail>front)
{
int now=dl[front];
int temp=root[depth_now];
if(depth[now]!=depth_now)
{
depth_now=depth[now];
temp=root[depth_now-1];
}
root[depth_now]=++sgt.cnt;
sgt.Change(dfn[now],a[now],root[depth_now],temp,1,n);
for(int i=0;i<int(e[now].size());i++)
if(depth[e[now][i]]>depth[now])
dl[tail++]=e[now][i];
front++;
}
}
int main()
{
n=read(),r=read();
for(int i=1;i<=n;i++)
a[i]=read();
for(int i=1;i<n;i++)
{
int s=read(),t=read();
e[s].push_back(t);
e[t].push_back(s);
}
depth[r]=1;
dfs(r);
sgt.Build(0,1,n);
bfs();
int m=read(),lans=0;
for(int i=1;i<=m;i++)
{
int x=read(),K=read();
x=((x+lans)%n)+1,K=(K+lans)%n;
int temp=min(depth[x]+K,depth_MAX);
lans=sgt.Query(dfn[x],dfn[x]+size[x]-1,root[temp],1,n);
printf("%d\n",lans);
}
return 0;
}
|
