luogu 3812 【模板】 线性基

线性基是一个支持在集合里插入数并查询最大子集异或值

 #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 100100
 #define MOD 998244353
 #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 pb(i,x) vec[i].push_back(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 ll read()
 {
     ll x=,f=;char ch=getchar();
     while(!isdigit(ch)) {if(ch=='-') f=-;ch=getchar();}
     while(isdigit(ch)) {x=x*+ch-'';ch=getchar();}
     return x*f;
 }
 ll p[];int n,m;
 void ins(ll x) {dwn(i,,) if(x>>i&1LL) {if(!p[i]) {p[i]=x;break;}x^=p[i];}}
 ll query(ll res=) {dwn(i,,) res=max(res,res^p[i]);return res;}
 int main()
 {
     n=read();rep(i,,n) ins(read());printf("%lld\n",query());
 }