T飞了的回滚莫队,求大佬查错

//
//  main.cpp
//  SP20644
//
//  Created by mac on 2020/10/18.
//
#include<bits/stdc++.h>
using namespace std;
#define int long long
struct cxk{
    int l,r,id;
}q[500002];
int n,m;
int s[500002];
int rb[500002];
int be[500002];
int ma[1000002];
int mi[1000002];
int ans[500002];
int maxx;
int giao=0;
bool cmp(cxk a,cxk b)
{
    if(be[a.l]!=be[b.l])return a.r<b.r;
    return a.l<b.l;
}
inline void read(int &num)
{
    int sign=1;
    char c;
    while((c=getchar())<'0'||c>'9')
        if(c=='-')sign=-1;
    num=c-'0';
    while((c=getchar())>='0'&&c<='9')
        num=(num<<1)+(num<<3)+c-'0';
    num*=sign;
}
signed main( )
{
    read(n);
    read(m);
    n++;
    s[1]=n+1;
    for(int i=2;i<=n;i++)
    {
        read(s[i]);
        s[i]=s[i]+s[i-1];
    }
    /*int gn=sqrt(n);
    int gnn=ceil((double)n/gn);
    for(int i=1;i<=gnn;++i)
    {
        rb[i]=i*gn;
        for(int j=i*gn-gn+1;j<=i*gn&&j<=n;j++)be[j]=i;
    }
    rb[gnn]=n;*/
    int len=sqrt(n);
    for(int i=1;i<=n;++i)be[i]=(i-1)/len+1;
    for(int i=1;i<=len+1;++i)rb[i]=min(i*len,n);
    for(int i=1;i<=m;++i)
    {
        read(q[i].l);
        read(q[i].r );
        q[i].r++;
        q[i].id=i;
    }
    sort(q+1,q+m+1,cmp);
    int r=0;
    int l=0;
    int maxx=0;
    int lastblock=0;
    for(int i=1;i<=m;++i)
    {
        if(be[q[i].l]==be[q[i].r])
        {
            maxx=0;
            for(int j=q[i].r;j>=q[i].l;--j)ma[s[j]]=0;
            for(int j=q[i].r;j>=q[i].l;--j)
            {
                if(ma[s[j]]==0)ma[s[j]]=j;
                else maxx=max(maxx,ma[s[j]]-j);
            }
            for(int j=q[i].r;j>=q[i].l;--j)ma[s[j]]=0;
            ans[q[i].id]=maxx;
            continue;
        }
       /* if(giao^be[q[i].l])
        {
            giao=be[q[i].l];
            while(r>rb[giao])
            {
                ma[s[r]]=mi[s[r]]=0;
                r--;
            }
            while(l<rb[giao]+1)
            {
                ma[s[l]]=mi[s[l]]=0;
                l++;
            }
            maxx=0;
            r=l-1;
        }*/
        if(lastblock^be[q[i].l])
        {
            while(r>rb[be[q[i].l]])
            {
                ma[s[r]]=mi[s[r]]=0;
                --r;
            }
            while(l<rb[be[q[i].l]]+1)
            {
                ma[s[l]]=mi[s[l]]=0;
                ++l;
            }
            r=l-1;
            maxx=0;
            lastblock=be[q[i].l];
        }
        
        while(r<q[i].r)
        {
            ++r;
            if(mi[s[r]]==0)mi[s[r]]=ma[s[r]]=r;
            else
            {
                ma[s[r]]=r;
                maxx=max(maxx,r-mi[s[r]]);
            }
        }
        int ll=l;
        int res=maxx;
        while(ll>q[i].l)
        {
            --ll;
            if(!ma[s[ll]])ma[s[ll]]=ll;
            else res=max(res,ma[s[ll]]-ll);
        }
        while(ll<l)
        {
            if(ma[s[ll]]==ll)ma[s[ll]]=0;
            ++ll;
        }
        ans[q[i].id]=res;
    }
    for(int i=1;i<=m;i++)printf("%lld\n",ans[i]);
    return 0;
}