bzoj 3261 最大异或和

可持久化$trie$树裸题，对于查询相当于查询$sum[p-1]space mathrm{xor} space sum[n] space mathrm{xor} space x$最大

把所有$sum$加入即可

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<cmath>
#include<algorithm>
#include<queue>
#include<vector>
#include<map>
#include<set>
#define ll long long
#define db double
#define inf 2139062143
#define MAXN 600100
#define rep(i,s,t) for(register int i=(s),i##__end=(t);i<=i##__end;++i)
#define dwn(i,s,t) for(register int i=(s),i##__end=(t);i>=i##__end;--i)
#define ren for(register int i=fst[x];i;i=nxt[i])
#define Fill(x,t) memset(x,t,sizeof(x))
#define pls(a,b) (a+b)%MOD
#define mns(a,b) (a-b+MOD)%MOD
#define mul(a,b) (1LL*(a)*(b))%MOD
using namespace std;
inline int read()
{
    int x=0,f=1;char ch=getchar();
    while(!isdigit(ch)) {if(ch=='-') f=-1;ch=getchar();}
    while(isdigit(ch)) {x=x*10+ch-'0';ch=getchar();}
    return x*f;
}
int n,m,tr[MAXN*26][2],rt[MAXN],val[MAXN*26],tot,sum;
void ins(int &k,int kk,int t,int x)
{
    k=++tot,val[k]=val[kk]+1;if(t<0) return ;int i=(x>>t)&1;tr[k][!i]=tr[kk][!i];
    ins(tr[k][i],tr[kk][i],t-1,x);
}
int query(int k,int kk,int t,int x)
{
    if(t<0) return 0;int i=(x>>t)&1;if(val[tr[k][!i]]>val[tr[kk][!i]])
        return (1<<t)+query(tr[k][!i],tr[kk][!i],t-1,x);
    else return query(tr[k][i],tr[kk][i],t-1,x);
}
int main()
{
    n=read(),m=read();ins(rt[0],0,25,0);
    rep(i,1,n) sum^=read(),ins(rt[i],rt[i-1],25,sum);
    char s[3];int a,b,c;while(m--)
    {
        scanf("%s",s);a=read();
        if(s[0]=='A') sum^=a,n++,ins(rt[n],rt[n-1],25,sum);
        else
        {
            a=(a>1?rt[a-2]:0),b=read()-1,c=read();
            printf("%d
",query(rt[b],a,25,sum^c));
        }
    }
}