本地AC ， 提交TLE

本地运行用 clock 看只有 600多ms 但交上去就会T，求巨佬救救

#include<bits/stdc++.h>
//#define int long long
//#define lld d
using namespace std;
int n,m,a[1000001];
int cnt,len,bel[1000001];
unordered_map<int,int>H,ans;
struct Node{
    int l,r;
    unordered_map<int,int>s;
    vector<int>num;
}fk[10001];
int pre[351][40001],s[351][351];
int lastans;
int read(){
    int k=0;
    char ch=getchar();
    while(!isdigit(ch)) ch=getchar();
    while(isdigit(ch)){
        k=(k<<1)+(k<<3)+(ch^48);
        ch=getchar();
    }
    return k;
}
signed main(){
//  freopen("4168.in","r",stdin);
//  freopen("4168.out","w",stdout);
//  scanf("%d %d",&n,&m);
    n=read();m=read();
    len=sqrt(n);
    for(int i=1;i<=n;i++){
        //scanf("%d",&a[i]);
        a[i]=read();
        bel[i]=(i/len)+1;
        if(!H[a[i]]) H[a[i]]=++cnt;
        ans[H[a[i]]]=a[i];
        if(!fk[bel[i]].s[a[i]])
            fk[bel[i]].num.push_back(a[i]);
        fk[bel[i]].s[a[i]]++;
    }
    fk[bel[n]].r=n;

    for(int i=1;i<=bel[n];i++){
        for(int j=1;j<=cnt;j++)
            pre[i][j]=pre[i-1][j]+fk[i].s[ans[j]];
    }
    for(int i=1;i<=bel[n];i++){
        int now=0;
        unordered_map<int,int>nows;
        for(int j=i;j<=bel[n];j++){
            for(auto k:fk[j].num){
                nows[k]+=fk[j].s[k];
                now=nows[k]==nows[now]?(k>now?now:k):(nows[k]>nows[now]?k:now);
            }
            s[i][j]=now;
        }
    }

    while(m--){
        int l=read(),r=read();
        l=(l+lastans-1)%n+1;
        r=(r+lastans-1)%n+1;
        if(l>r) swap(l,r);
        int now=0;
    //  cout<<"A"<<endl;
        unordered_map<int,int>nows;
        if(bel[r]-bel[l]<=1){
    //      cout<<"C"<<endl;
            for(int i=l;i<=r;i++){
                nows[a[i]]++;
                now=nows[a[i]]==nows[now]?(a[i]>now?now:a[i]):(nows[a[i]]>nows[now]?a[i]:now);
            }
            printf("%d\n",now);
            lastans=now;
            continue;
        }   
        else{
        //  cout<<"B"<<endl;
            for(int i=l;bel[i]==bel[l];i++){
                if(!nows[a[i]])
                    nows[a[i]]+=pre[bel[r]-1][H[a[i]]]-pre[bel[l]][H[a[i]]];
                nows[a[i]]++;
                now=nows[a[i]]==nows[now]?(a[i]>now?now:a[i]):(nows[a[i]]>nows[now]?a[i]:now);
            }
            for(int i=r;bel[i]==bel[r];i--){
                if(!nows[a[i]])
                    nows[a[i]]+=pre[bel[r]-1][H[a[i]]]-pre[bel[l]][H[a[i]]];
                nows[a[i]]++;
                now=nows[a[i]]==nows[now]?(a[i]>now?now:a[i]):(nows[a[i]]>nows[now]?a[i]:now);
            }
            int nowk=s[bel[l]+1][bel[r]-1];
            if(!nows[nowk]){
                nows[nowk]+=(pre[bel[r]-1][H[nowk]]-pre[bel[l]][H[nowk]]);
                now=nows[nowk]==nows[now]?(nowk>now?now:nowk):(nows[nowk]>nows[now]?nowk:now);  
            }
            printf("%d\n",now);
            lastans=now;
        }
    }
//  cout<<clock()<<endl;
    return 0;
}