二逼平衡树 树套树

不用解释了吧……经典板子……

题解也没什么写的……就是一句话：一遍写对省了再debug麻烦。

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<cstdlib>
using namespace std;
#define ls(x) (x->ch[0])
#define rs(x) (x->ch[1])
#define size(x) ((x) ? (x->size) : (0))
#define Lson l,mid,id<<1
#define Rson mid+1,r,id<<1|1
const int maxn=50010,inf=1000000000;
struct Node
{
    int key,val,size,num;
    Node *ch[2];
    void Init(int x=0)
    {
        val=x;size=1;num=1;key=rand();
        ch[0]=ch[1]=NULL;
    }
    bool operator <(const Node &x)const
    {
        return key<x.key;
    }
    int Cmp(int x)const
    {
        if(x==val)return -1;
        return x>val;
    }
    void Maintain()
    {
        size=num;
        if(ch[0])size+=ch[0]->size;
        if(ch[1])size+=ch[1]->size;
    }
};
Node *root[maxn<<2];
Node node[maxn<<6];
int tot=1,tmp,n,m,a[maxn];
Node* NewNode(int v)
{
    node[tot].Init(v);
    return &node[tot++];
}
void Rotate(Node* &rt,int d)
{
    Node *t=rt->ch[d^1];
    rt->ch[d^1]=t->ch[d];t->ch[d]=rt;
    rt->Maintain();t->Maintain();
    rt=t;
}
void Insert(Node* &rt,int x)
{
    if(!rt)rt=NewNode(x);
    else
    {
        int d=rt->Cmp(x);
        if(d<0)rt->num++;
        else
        {
            Insert(rt->ch[d],x);
            if(rt->ch[d]>rt)Rotate(rt,d^1);
        }
    }
    rt->Maintain();
}
void Build(int l,int r,int id,int x,int num)
{
    Insert(root[id],num);
    if(l==r)return;
    int mid=(l+r)>>1;
    if(x<=mid)Build(Lson,x,num);
    else Build(Rson,x,num);
}
void Ask_Rank(Node* &rt,int x)
{
    if(!rt)return;
    if(x==rt->val)
    {
        tmp+=size(ls(rt));
        return;
    }
    if(rt->val>x)Ask_Rank(ls(rt),x);
    else
    {
        tmp+=size(ls(rt))+rt->num;
        Ask_Rank(rs(rt),x);
    }
}
void Get_Rank(int l,int r,int id,int x,int y,int num)
{
    if(l==x&&r==y)
    {
        Ask_Rank(root[id],num);
        return;
    }
    int mid=(l+r)>>1;
    if(mid>=y)Get_Rank(Lson,x,y,num);
    else if(mid<x)Get_Rank(Rson,x,y,num);
    else
    {
        Get_Rank(Lson,x,mid,num);
        Get_Rank(Rson,mid+1,y,num);
    }
}
void Get_Index(int x,int y,int k)
{
    int num,l=0,r=inf,mid;
    while(l<=r)
    {
        mid=(l+r)>>1;tmp=1;
        Get_Rank(1,n,1,x,y,mid);
        if(tmp<=k)
        {
            l=mid+1;
            num=mid;
        }
        else r=mid-1;
    }
    printf("%d
",num);
}
void Delete(Node* &rt,int x)
{
    int d=rt->Cmp(x);
    if(d<0)
    {
        if(rt->num==1)
        {
            if(ls(rt)&&rs(rt))
            {
                int d2=ls(rt)>rs(rt);
                Rotate(rt,d2);
                Delete(rt->ch[d2],x);
            }
            else
            {
                Node *t=NULL;
                if(ls(rt))t=ls(rt);
                else t=rs(rt);
                rt=t;
            }
        }
        else rt->num--;
    }
    else Delete(rt->ch[d],x);
    if(rt)rt->Maintain();
}
void Change(int l,int r,int id,int x,int nxt,int cur)
{
    Delete(root[id],cur);
    Insert(root[id],nxt);
    if(l==r)return;
    int mid=(l+r)>>1;
    if(x<=mid)Change(Lson,x,nxt,cur);
    else Change(Rson,x,nxt,cur);
}
void Ask_Pre(Node* &rt,int x)
{
    if(!rt)return;
    if(x>rt->val)
    {
        tmp=max(tmp,rt->val);
        Ask_Pre(rs(rt),x);
    }
    else Ask_Pre(ls(rt),x);
}
void Get_Pre(int l,int r,int id,int x,int y,int num)
{
    if(l==x&&r==y)
    {
        Ask_Pre(root[id],num);
        return;
    }
    int mid=(l+r)>>1;
    if(mid>=y)Get_Pre(Lson,x,y,num);
    else if(mid<x)Get_Pre(Rson,x,y,num);
    else
    {
        Get_Pre(Lson,x,mid,num);
        Get_Pre(Rson,mid+1,y,num);
    }
}
void Ask_Suf(Node* &rt,int x)
{
    if(!rt)return;
    if(x<rt->val)
    {
        tmp=min(tmp,rt->val);
        Ask_Suf(ls(rt),x);
    }
    else Ask_Suf(rs(rt),x);
}
void Get_Suf(int l,int r,int id,int x,int y,int num)
{
    if(l==x&&r==y)
    {
        Ask_Suf(root[id],num);
        return;
    }
    int mid=(l+r)>>1;
    if(mid>=y)Get_Suf(Lson,x,y,num);
    else if(mid<x)Get_Suf(Rson,x,y,num);
    else
    {
        Get_Suf(Lson,x,mid,num);
        Get_Suf(Rson,mid+1,y,num);
    }
}
int haha()
{
    freopen("psh.in","r",stdin);
    freopen("psh.out","w",stdout);
    int op,l,r,k,pos;
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;i++)scanf("%d",&a[i]);
    for(int i=1;i<=n;i++)Build(1,n,1,i,a[i]);
    while(m--)
    {
        scanf("%d",&op);
        switch(op)
        {
            case 1:scanf("%d%d%d",&l,&r,&k);tmp=1;
                    Get_Rank(1,n,1,l,r,k);
                    printf("%d
",tmp);break;
            case 2:scanf("%d%d%d",&l,&r,&k);
                    Get_Index(l,r,k);break;
            case 3:scanf("%d%d",&pos,&k);
                    Change(1,n,1,pos,k,a[pos]);
                    a[pos]=k;break;
            case 4:scanf("%d%d%d",&l,&r,&k);tmp=0;
                    Get_Pre(1,n,1,l,r,k);
                    printf("%d
",tmp);break;
            case 5:scanf("%d%d%d",&l,&r,&k);tmp=inf;
                    Get_Suf(1,n,1,l,r,k);
                    printf("%d
",tmp);break;
        }
    }
    //while(1);
}
int sb=haha();
int main(){;}