There is an integer sequence a of length n and there are two kinds of operations:
0 l r: select some numbers from al…ar so that their xor sum is maximum, and print the maximum value.
1 x: append x to the end of the sequence and let n=n+1.
Input
There are multiple test cases. The first line of input contains an integer T(T≤10), indicating the number of test cases.
For each test case:
The first line contains two integers n,m(1≤n≤5×105,1≤m≤5×105), the number of integers initially in the sequence and the number of operations.
The second line contains n integers a1,a2,…,an(0≤ai<230), denoting the initial sequence.
Each of the next m lines contains one of the operations given above.
It’s guaranteed that ∑n≤106,∑m≤106,0≤x<230.
And operations will be encrypted. You need to decode the operations as follows, where lastans denotes the answer to the last type 0 operation and is initially zero:
For every type 0 operation, let l=(l xor lastans)mod n + 1, r=(r xor lastans)mod n + 1, and then swap(l, r) if l>r.
For every type 1 operation, let x=x xor lastans.
Output
For each type 0 operation, please output the maximum xor sum in a single line.
Sample Input
1
3 3
0 1 2
0 1 1
1 3
0 3 4
Sample Output
1
3
注意每次操作不管是增加还是询问都要进行在线操作,下面的代码,询问的时候可以直接用一个函数解决,但是额外增加一个数组可以对区间线性基做更多操作,方便修改
#include<bits/stdc++.h>
#define maxn 500005
using namespace std;
int b[maxn][35],pos[maxn][35];
bool insert(int h,int x)
{
for(int i=0;i<=31;++i)
b[h][i]=b[h-1][i],pos[h][i]=pos[h-1][i];
int tmp=h;
for(int i=31;i>=0;--i)
if(x&(1<<i))
{
if(b[h][i])
{
if(pos[h][i]<tmp)
{
swap(pos[h][i],tmp);
swap(b[h][i],x);
}
x^=b[h][i];
}
else
{
b[h][i]=x;
pos[h][i]=tmp;
return true;
}
}
return false;
}
int a[35];
int get_max()
{
int ret = 0;
for(int i = 32;i >= 0;--i)
if((ret^a[i]) > ret)
{
ret ^= a[i];
}
return ret;
}
int main()
{
int t,n,m,k,temp,op,x;
scanf("%d",&t);
while(t--)
{
memset(b,0,sizeof(b));
memset(pos,0,sizeof(pos));
scanf("%d%d",&n,&m);
for(int i=1;i<=n;i++)
{
scanf("%d",&temp);
insert(i,temp);
}
int ans=0;
while(m--)
{
scanf("%d",&op);
if(op==0)
{
memset(a,0,sizeof(a));
int l,r;
scanf("%d%d",&l,&r);
l=(l^ans)%n+1;
r=(r^ans)%n+1;
if(l>r)
swap(l,r);
for(int i=31;i>=0;--i)
{
if(pos[r][i]>=l)
{
a[i]=b[r][i];
}
}
ans=get_max();
printf("%d\n",ans);
}
else
{
scanf("%d",&x);
n++;
x^=ans;
insert(n,x);
}
}
}
}