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dfs序作为下标,深度作为时间轴

#include<bits/stdc++.h>
namespace ZDY{
    #pragma GCC optimize(3)
    #define il __inline__ __attribute__ ((always_inline))
    #define register
    #define ll long long
    #define ull unsigned long long
    #define db double
    #define sht short
    #define MB template <class T>il
    #define Fur(i,x,y) for(int i(x);i<=y;++i)
    #define Fdr(i,x,y) for(int i(x);i>=y;--i)
    #define fl(i,x) for(int i(head[x]),to;to=e[i].to,i;i=e[i].nxt)
    #define clr(x,y) memset(x,y,sizeof(x))
    #define cpy(x,y) memcpy(x,y,sizeof(x))
    #define fin(s) freopen(s".in","r",stdin)
    #define fout(s) freopen(s".out","w",stdout)
    #define fcin ios::sync_with_stdio(false)
    #define l2(n) ((int)(log2(n)))
    #define inf 2122219134
    MB T ABS(T x){return x>0?x:-x;}
    MB T MAX(T x,T y){return x>y?x:y;}
    MB T MIN(T x,T y){return x<y?x:y;}
    MB T GCD(T x,T y){return y?GCD(y,x%y):x;}
    MB void SWAP(T &x,T &y){T t=x;x=y;y=t;}
}using namespace ZDY;using namespace std;
namespace IO{const int str=1<<20;static char in_buf[str],*in_s,*in_t;bool __=0;il char gc(){return (in_s==in_t)&&(in_t=(in_s=in_buf)+fread(in_buf,1,str,stdin)),in_s==in_t?EOF:*in_s++;}il void in(string &ch){ch.clear();if(__)return;char c;while((c=gc())!=EOF&&isspace(c));if(c==EOF){__=1;return;}ch+=c;while((c=gc())!=EOF&&!isspace(c))ch+=c;if(c==EOF)__=1;}il void in(char &ch){if(__)return;char c;while((c=gc())!=EOF&&isspace(c));if(c==EOF)__=1;else ch=c;}il void in(char *ch){*ch='\0';if(__)return;char c;while((c=gc())!=EOF&&isspace(c));if(c==EOF){__=1;return;}*ch=c;ch++;while((c=gc())!=EOF&&!isspace(c))*ch=c,ch++;if(c==EOF)__=1;*ch='\0';}template<typename T>il void in(T &x){if(__)return;char c=gc();bool f=0;while(c!=EOF&&(c<'0'||c>'9'))f^=(c=='-'),c=gc();if(c==EOF){__=1;return;}x=0;while(c!=EOF&&'0'<=c&&c<='9')x=x*10+c-48,c=gc();if(c==EOF)__=1;if(f)x=-x;}template<typename T,typename ... arr>il void in(T &x,arr & ... y){in(x),in(y...);}const char ln='\n';static char out_buf[str],*out_s=out_buf,*out_t=out_buf+str;il void flush(){fwrite(out_buf,1,out_s-out_buf,stdout);out_s=out_buf;}il void pt(char c){(out_s==out_t)?(fwrite(out_s=out_buf,1,str,stdout),*out_s++=c):(*out_s++=c);}il void out(const char* s){while(*s)pt(*s++);}il void out(char* s){while(*s)pt(*s++);}il void out(char c){pt(c);}il void out(string s){for(int i=0;s[i];i++)pt(s[i]);}template<typename T>il void out(T x){if(!x){pt('0');return;}if(x<0)pt('-'),x=-x;char a[50],t=0;while(x)a[t++]=x%10,x/= 10;while(t--)pt(a[t]+'0');}template<typename T,typename ... arr>il void out(T x,arr & ... y){out(x),out(y...);}}using namespace IO;
#define N 100011
#define int ll
int n,q,cnt=0,head[N],c[N];
struct edge{
    int to,nxt;
}e[N<<1];
il void add(int x,int y){
    e[++cnt].to=y;e[cnt].nxt=head[x];head[x]=cnt;
}
int s[N*30],ls[N*30],rs[N*30],sz=0,rt[N];
void build(int l,int r,int &x){
    s[x=++sz]=inf;
    if(l==r)return;
    int m=(l+r)>>1;
    build(l,m,ls[x]);build(m+1,r,rs[x]);
}
void ins(int p,int v,int l,int r,int &x,int pre){
    x=++sz;
    ls[x]=ls[pre];
    rs[x]=rs[pre];
    if(l==r){
        s[x]=v;
        return;
    }
    int m=(l+r)>>1;
    if(p<=m)ins(p,v,l,m,ls[x],ls[pre]);
    else ins(p,v,m+1,r,rs[x],rs[pre]);
    s[x]=MIN(s[ls[x]],s[rs[x]]);
}
int ask(int L,int R,int l,int r,int x){
    if(L<=l&&r<=R)return s[x];
    int m=(l+r)>>1,ans=inf;
    if(L<=m)ans=ask(L,R,l,m,ls[x]);
    if(R>m)ans=MIN(ans,ask(L,R,m+1,r,rs[x]));
    return ans;
}
int st[N],ed[N],dfn=0,d[N],mxd=0;
void dfs(int x,int f){
    d[x]=d[f]+1;mxd=MAX(mxd,d[x]);
    st[x]=++dfn;
    fl(i,x)if(to!=f)dfs(to,x);
    ed[x]=dfn;
}
void bfs(){
    queue<int>q;q.push(1);
    build(1,n,rt[0]);
    int x,ld=0,pre;
    while(!q.empty()){
        x=q.front();q.pop();
        if(d[x]!=ld)pre=rt[d[x]-1];
        else pre=rt[d[x]];
        ins(st[x],c[x],1,n,rt[d[x]],pre);
        fl(i,x)if(d[to]>d[x])q.push(to);
        ld=d[x];
    }
}
signed main(){
    in(n,q);
    Fur(i,1,n)in(c[i]);
    int x,y,la=0;
    Fur(i,1,n-1)in(x,y),add(x,y),add(y,x);
    dfs(1,0);
    bfs();
    while(q--){
        in(x,y);
        x=(x+la)%n+1;
        y=(y+la)%n;
        la=ask(st[x],ed[x],1,n,rt[MIN(d[x]+y,mxd)]);
        out(la,ln);
    }
    flush();
}
LG CF893F Subtree-Minimum-Query
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