bzoj2741【FOTILE模拟赛】L

#include<cstdio>
#include<cstdlib>
#include<iostream>
#include<fstream>
#include<algorithm>
#include<cstring>
#include<string>
#include<cmath>
#include<queue>
#include<stack>
#include<map>
#include<utility>
#include<set>
#include<bitset>
#include<vector>
#include<functional>
#include<deque>
#include<cctype>
#include<climits>
#include<complex>
//#include<bits/stdc++.h>适用于CF,UOJ，但不适用于poj
 
using namespace std;

typedef long long LL;
typedef double DB;
typedef pair<int,int> PII;
typedef complex<DB> CP;

#define mmst(a,v) memset(a,v,sizeof(a))
#define mmcy(a,b) memcpy(a,b,sizeof(a))
#define fill(a,l,r,v) fill(a+l,a+r+1,v)
#define re(i,a,b)  for(i=(a);i<=(b);i++)
#define red(i,a,b) for(i=(a);i>=(b);i--)
#define ire(i,x) for(typedef(x.begin()) i=x.begin();i!=x.end();i++)
#define fi first
#define se second
#define m_p(a,b) make_pair(a,b)
#define p_b(a) push_back(a)
#define SF scanf
#define PF printf
#define two(k) (1<<(k))

template<class T>inline T sqr(T x){return x*x;}
template<class T>inline void upmin(T &t,T tmp){if(t>tmp)t=tmp;}
template<class T>inline void upmax(T &t,T tmp){if(t<tmp)t=tmp;}

const DB EPS=1e-9;
inline int sgn(DB x){if(abs(x)<EPS)return 0;return(x>0)?1:-1;}
const DB Pi=acos(-1.0);

inline int gint()
  {
        int res=0;bool neg=0;char z;
        for(z=getchar();z!=EOF && z!=‘-‘ && !isdigit(z);z=getchar());
        if(z==EOF)return 0;
        if(z==‘-‘){neg=1;z=getchar();}
        for(;z!=EOF && isdigit(z);res=res*10+z-‘0‘,z=getchar());
        return (neg)?-res:res; 
    }
inline LL gll()
  {
      LL res=0;bool neg=0;char z;
        for(z=getchar();z!=EOF && z!=‘-‘ && !isdigit(z);z=getchar());
        if(z==EOF)return 0;
        if(z==‘-‘){neg=1;z=getchar();}
        for(;z!=EOF && isdigit(z);res=res*10+z-‘0‘,z=getchar());
        return (neg)?-res:res; 
    }

const int maxN=12000;
const int maxcnt=120;

struct Tnode
  {
      Tnode *son[2];
        inline Tnode(){son[0]=son[1]=0;}      
  };

int N,Q;
int len,cnt,id[maxN+10],l[maxcnt+10],r[maxcnt+10];
int a[maxN+100];
Tnode *rt[maxcnt+10];
int f[maxN+100][maxcnt+10];
int g[maxcnt+100][maxcnt+10];
int lastans;

int t[40];
inline void insert(Tnode *p,int v)
  {
      int i;
      re(i,1,31)t[i]=v&1,v>>=1;
      red(i,31,1)
        {
            if(!p->son[t[i]])p->son[t[i]]=new Tnode;
            p=p->son[t[i]];
        }
  }
inline int find(Tnode *p,int v)
  {
      int i,res=0;
      re(i,1,31)t[i]=v&1,v>>=1;
      red(i,31,1)
        {
            int to=(p->son[t[i]^1])?t[i]^1:t[i];
            res=(res<<1)+to;
            p=p->son[to];
        }
      return res;
  }

int main()
  {
      freopen("bzoj2741.in","r",stdin);
      freopen("bzoj2741.out","w",stdout);
      int i,j;
      N=gint()+1;Q=gint();
        re(i,2,N)a[i]=gint();
        re(i,1,N)a[i]^=a[i-1];
      len=int(sqrt(DB(N)));
      re(i,1,N)
        {
            if((i-1)%len==0)r[cnt]=i-1,l[++cnt]=i;
            id[i]=cnt;
        }
      r[cnt]=N;
      re(i,1,cnt)rt[i]=new Tnode;
      re(i,1,N)insert(rt[id[i]],a[i]);
      re(i,1,N)re(j,1,cnt)f[i][j]=a[i]^find(rt[j],a[i]);
      re(i,1,N)re(j,1,cnt)upmax(g[id[i]][j],f[i][j]);
      lastans=0;
      while(Q--)
        {
            int x=gint(),y=gint();
            int L=int( min( (LL(x)+LL(lastans))%LL(N-1)+1 , (LL(y)+LL(lastans))%LL(N-1)+1 ) ) +1 ;
            int R=int( max( (LL(x)+LL(lastans))%LL(N-1)+1 , (LL(y)+LL(lastans))%LL(N-1)+1 ) ) +1 ;
            L--;
            lastans=0;
            if(id[L]==id[R] || id[L]+1==id[R])
              {
                  re(i,L,R)re(j,i,R)upmax(lastans,a[i]^a[j]);
              }
            else
              {
                int p=(L==l[id[L]])?id[L]:id[L]+1,q=(R==r[id[R]])?id[R]:id[R]-1;
                re(i,p,q)re(j,i,q) upmax(lastans,g[i][j]);
                re(i,L,l[p]-1)re(j,p,q) upmax(lastans,f[i][j]);
                re(i,r[q]+1,R)re(j,p,q) upmax(lastans,f[i][j]);
                re(i,L,l[p]-1)re(j,r[q]+1,R)upmax(lastans,a[i]^a[j]);
                re(i,L,l[p]-1)re(j,i+1,l[p]-1)upmax(lastans,a[i]^a[j]);
                re(i,r[q]+1,R)re(j,i+1,R)upmax(lastans,a[i]^a[j]);
              }
            cout<<lastans<<endl;
        }
      return 0;
  }