BZOJ 4184: shallot

/**************************************************************
    Problem: 4184
    User: BeiYu
    Language: C++
    Result: Accepted
    Time:11256 ms
    Memory:37624 kb
****************************************************************/
 
#include <bits/stdc++.h>
using namespace std;
 
typedef long long LL;
const int N = 5e5+50;
const int M = 35;
 
int n;
map< int,int > mp;
LL pow2[M],ans[N];
 
struct Py {
    LL b[M];
    Py() { memset(b,0,sizeof(b)); }
    void insert(int x) {
        for(int i=M-1;~i;i--) if(x&pow2[i]) {
            if(!b[i]) { b[i]=x;break; }
            else x^=b[i];
        }
    }
    LL GetAns() {
        LL ans=0;
        for(int i=M-1;~i;i--) if((ans^b[i])>ans) ans^=b[i];
        return ans;
    }
}piyan;
struct SegMentTree {
    vector< int > d[N<<2];
    #define lc (o<<1)
    #define rc (o<<1|1)
    #define mid ((l+r)>>1)
     
    void insert(int o,int l,int r,int L,int R,int x) {
        if(L<=l && r<=R) return void(d[o].push_back(x));
        if(L<=mid) insert(lc,l,mid,L,R,x);
        if(R>mid) insert(rc,mid+1,r,L,R,x);
    }
    void DFS(int o,int l,int r,Py py) {
        for(vector< int > ::iterator i=d[o].begin();i!=d[o].end();i++) py.insert(*i);
        if(l==r) return void(ans[l]=py.GetAns());
        DFS(lc,l,mid,py),DFS(rc,mid+1,r,py);
    }
}seg;
 
 
inline int in(int x=0,char ch=getchar(),int v=1) {
    while(ch>‘9‘ || ch<‘0‘) v=ch==‘-‘ ? -1 : v,ch=getchar();
    while(ch>=‘0‘ && ch<=‘9‘) x=x*10+ch-‘0‘,ch=getchar();return x*v;
}
int main() {
    n=in();
    for(int i=1;i<=n;i++) {
        int x=in();
        if(x>=0) mp[x]=i;
        else x=-x,seg.insert(1,1,n,mp[x],i-1,x),mp.erase(x);
    }
    for(map< int,int > ::iterator i=mp.begin();i!=mp.end();i++) 
        if((*i).second) seg.insert(1,1,n,(*i).second,n,(*i).first);
    pow2[0]=1;for(int i=1;i<M;i++) pow2[i]=pow2[i-1]<<1;
    seg.DFS(1,1,n,piyan);
    for(int i=1;i<=n;i++) printf("%lld\n",ans[i]);
    return 0;
}