BZOJ 3689: 异或之 可持久化trie+堆

和超级钢琴几乎是同一道题吧...

code:

#include <bits/stdc++.h>
#define N 200006
#define ll long long
#define setIO(s) freopen(s".in","r",stdin)  , freopen(s".out","w",stdout)
using namespace std;
char buf[100000],*p1,*p2;
#define nc() (p1==p2&&(p2=(p1=buf)+fread(buf,1,100000,stdin),p1==p2)?EOF:*p1++)
int rd()
{
    int x=0; char s=nc();
    while(s<'0') s=nc();
    while(s>='0') x=(((x<<2)+x)<<1)+s-'0',s=nc();
    return x;
}
namespace trie
{
    int tot;
    int cnt[N*30],ch[N*30][2];
    int newnode() { return ++tot; }
    void Insert(int pre,int &x,int v)
    {
        int now=x=newnode(),i;
        for(i=30;i>=0;--i)
        {
            int o=((v>>i)&1);
            ch[now][o^1]=ch[pre][o^1];
            ch[now][o]=newnode();
            pre=ch[pre][o];
            now=ch[now][o];
            cnt[now]=cnt[pre]+1;
        }
    }
    int query(int x,int y,int z)
    {
        int re=0,i;
        for(i=30;i>=0;--i)
        {
            int o=((z>>i)&1);
            if(ch[x][o]<ch[y][o])   x=ch[x][o],y=ch[y][o];
            else re+=(1<<i),x=ch[x][o^1],y=ch[y][o^1];
        }
        return re;
    }
};
struct node
{
    int o,l,r,val,pos;
    node(int o=0,int l=0,int r=0,int val=0,int pos=0):o(o),l(l),r(r),val(val),pos(pos){}
    bool operator<(node b) const
    {
        return b.val<val;
    }
};
priority_queue<node>q;
int A[N],rt[N],ar[N],id[N];
set<int>S[N];
set<int>::iterator it;
int main()
{
    // setIO("input");
    int i,j,n,k,ou=0;
    n=rd(),k=rd();
    for(i=1;i<=n;++i)
    {
        A[i]=rd();
        id[i]=ar[i]=A[i];
        trie::Insert(rt[i-1],rt[i],A[i]);
    }
    sort(ar+1,ar+1+n);
    for(i=1;i<=n;++i)    id[i]=lower_bound(ar+1,ar+1+n,id[i])-ar;
    for(i=1;i<=n;++i)    S[id[i]].insert(i);
    for(i=1;i<n;++i)
    {
        int l=i+1,r=n;
        int tmp=trie::query(rt[l-1],rt[r],A[i]);
        int idx=lower_bound(ar+1,ar+1+n,A[i]^tmp)-ar;
        int pos=*S[idx].lower_bound(l);
        q.push(node(i,l,r,tmp,pos));
    }
    while(ou<k)
    {
        node e=q.top(); q.pop();
        printf("%d ",e.val),++ou;
        int pos=e.pos;
        if(pos!=e.l)
        {
            int tmp=trie::query(rt[e.l-1],rt[pos-1],A[e.o]);
            int idx=lower_bound(ar+1,ar+1+n,A[e.o]^tmp)-ar;
            int t=*S[idx].lower_bound(e.l);
            q.push(node(e.o,e.l,pos-1,tmp,t));
        }
        if(pos!=e.r)
        {
            int tmp=trie::query(rt[pos],rt[e.r],A[e.o]);
            int idx=lower_bound(ar+1,ar+1+n,A[e.o]^tmp)-ar;
            int t=*S[idx].lower_bound(pos+1);
            q.push(node(e.o,pos+1,e.r,tmp,t));
        }
    }
    return 0;
}