【洛谷P4585】 [FJOI2015]火星商店问题 线段树分治+可持久化trie

感觉这个线段树分治和整体二分几乎相同啊~

code:

#include <bits/stdc++.h>
#define MAX 100300
#define ll long long
#define lson now<<1
#define rson now<<1|1
#define setIO(s) freopen(s".in","r",stdin)
using namespace std;
struct Buy  {int s,v,t; }q[MAX],tmp1[MAX],tmp2[MAX];
struct ASK  {int l,r,tl,tr,x; }p[MAX];
bool cmp(Buy a,Buy b) { return a.s<b.s; }
int rt[MAX];
namespace Trie
{
    struct Trie { int son[2],w; } t[MAX<<5];
    int tot,rt[MAX];
    void insert(int &x,int ff,int w,int now)
    {
        t[x=++tot]=t[ff];  t[x].w++;
        if(now==-1)  return;
        bool c=(w&(1<<now));
        insert(t[x].son[c],t[ff].son[c],w,now-1);
    }
    int Query(int l,int r,int w,int now)
    {
        if(now==-1)   return 0;
        bool c=w&(1<<now);
        int tmp=t[t[r].son[c^1]].w-t[t[l].son[c^1]].w;
        if(tmp)   return Query(t[l].son[c^1],t[r].son[c^1],w,now-1)+(1<<now);
        else return Query(t[l].son[c],t[r].son[c],w,now-1);
    }
};
int n,m,ans[MAX];
vector<int>seg[MAX<<2];
int cnt1,cnt2;
void Modify(int now,int l,int r,int L,int R,int x)
{
    if(L>R)   return;
    if(l>=L&&r<=R)   { seg[now].push_back(x);  return; }
    int mid=(l+r)>>1;
    if(L<=mid)   Modify(lson,l,mid,L,R,x);
    if(R>mid)    Modify(rson,mid+1,r,L,R,x);
}
int S[MAX],top;
int find(int x)
{
    int l=1,r=top,re=0;
    while(l<=r)
    {
        int mid=(l+r)>>1;
        if(S[mid]<=x)   re=mid,l=mid+1;
        else r=mid-1;
    }
    return re;
}
void sol(int now,int L,int R)
{
    top=Trie::tot=0;
    for(int i=L;i<=R;++i)
    {
        S[++top]=q[i].s;
        Trie::insert(rt[top],rt[top-1],q[i].v,17);
    }
    for(int i=0;i<seg[now].size();++i)
    {
        int k=seg[now][i];
        int l=find(p[k].l-1), r=find(p[k].r);
        ans[k]=max(ans[k],Trie::Query(rt[l],rt[r],p[k].x,17));
    }
}
void divide(int now,int l,int r,int L,int R)
{
    if(L>R)  return;
    int mid=(l+r)>>1,t1=0,t2=0;
    sol(now,L,R);
    if(l==r)  return;
    for(int i=L;i<=R;++i)
    {
        if(q[i].t<=mid)    tmp1[++t1]=q[i];
        else tmp2[++t2]=q[i];
    }
    for(int i=1;i<=t1;++i)  q[i+L-1]=tmp1[i];
    for(int i=1;i<=t2;++i)  q[i+L-1+t1]=tmp2[i];
    divide(lson,l,mid,L,L+t1-1);
    divide(rson,mid+1,r,L+t1,R);
}
int main()
{
    // setIO("input");
    int i,j;
    scanf("%d%d",&n,&m);
    for(i=1;i<=n;++i)
    {
        int x;
        scanf("%d",&x);
        Trie::insert(rt[i],rt[i-1],x,17);
    }
    for(i=1;i<=m;++i)
    {
        int opt;
        scanf("%d",&opt);
        if(!opt)
        {
            int s,v;
            scanf("%d%d",&s,&v);
            ++cnt1;
            q[cnt1]=(Buy){s,v,cnt1};
        }
        else
        {
            int l,r,x,d;
            scanf("%d%d%d%d",&l,&r,&x,&d);
            ans[++cnt2]=Trie::Query(rt[l-1],rt[r],x,17);
            p[cnt2]=(ASK){l,r,max(1,cnt1-d+1),cnt1,x};
        }
    }
    for(i=1;i<=cnt2;++i)   Modify(1,1,cnt1,p[i].tl,p[i].tr,i);
    sort(&q[1],&q[cnt1+1],cmp);
    divide(1,1,cnt1,1,cnt1);
    for(int i=1;i<=cnt2;++i)      printf("%d\n",ans[i]);
    return 0;
}