#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdlib>
#include<cstdio>
#include<string>
#include<vector>
#include<ctime>
#include<queue>
#include<stack>
#include<unordered_map>
#include<set>
#define ld long double
#define ll long long
#define ull unsigned long long
#define ui unsigned int
namespace FastIO
{
	template<typename T> inline void read(T&s)
	{
		s=0;char ch=getchar();
		while((ch>'9'||ch<'0')&&ch!='-')ch=getchar();
		bool tf=(ch=='-')&&(ch=getchar());
		while((ch>='0')&&(ch<='9'))s=(s<<1)+(s<<3)+ch-'0',ch=getchar();
		s=(tf?-s:s);
	}
	template<typename T,typename... Args> inline void read(T&x,Args&...args){read(x),read(args...);}
	template<typename T> inline void write(T x,char ch=' ')
	{
		if(x<0)x=-x,putchar('-');
		static char st[25];int top=0;
		do{st[top++]=x%10+'0',x/=10;}while(x);
		while(top)putchar(st[--top]);
		putchar(ch);
	}
}
using namespace FastIO;
using namespace std;
#define mid (l+((r-l)>>1))
namespace WrongAnswer_90
{
	int sum,l,r,n,x,y,cnt,a[1000001],root[1000001];
	unordered_map<int,int> mp;
	struct Node{int ls,rs,val;}t[21125001];
	void change(int now,int from,int k,int val)
	{
		l=1,r=n+1;
		while(l!=r)
		{
			t[now].val=t[from].val^val;
			if(k<=mid)t[now].rs=t[from].rs,now=t[now].ls?t[now].ls:t[now].ls=++cnt,from=t[from].ls,r=mid;
			else t[now].ls=t[from].ls,now=t[now].rs?t[now].rs:t[now].rs=++cnt,from=t[from].rs,l=mid+1;
		}
		t[now].val=t[from].val^val;
	}
	int ask(int now,int k)
	{
		sum=0,l=1,r=n+1;
		while(l!=r)
		{
			if(!now)return sum;
			if(k<=mid)sum^=t[t[now].rs].val,now=t[now].ls,r=mid;
			else now=t[now].rs,l=mid+1;
		}
		sum^=t[now].val;
		return sum;
	}
	inline void mian()
	{
		read(n);
		for(int i=1;i<=n;++i)read(a[i]);
		for(int i=n;i>=1;--i)
		{
			if(mp.find(a[i])==mp.end())root[i]=n+1;
			else root[i]=mp[a[i]];
			mp[a[i]]=i;
		}
		mp.clear();
		for(int i=1;i<=n;++i)sum=root[i],root[i]=++cnt,change(root[i],root[i-1],sum,a[i]),a[i]^=a[i-1];
		read(cnt);
		while(cnt--)read(x,y),write(ask(root[y],y+1)^ask(root[x-1],y+1)^a[y]^a[x-1],'\n');
	}
}
//#define LOCALJUDGE
signed main()
{
	WrongAnswer_90::mian();
	return 0;
}

MLE on #100

就我的水平看来已经到极限了

正解其实不需要可持久化

但是已经写了真的不想改了/kk/kk/kk

有没有哪位大佬帮忙卡卡