Treap template

Title: https://www.luogu.org/problemnew/show/P3369

Treap template.

code show as below:

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
int const MAXN=100005,inf=1e9;
int n,rt,cnt;
struct N{
    int ch [3], val, siz, pri, num;
}t[MAXN];
int newnode()
{
    int r=++cnt;
    t[r].siz=1;t[r].num=1;t[r].pri=rand();
    return r;
}
void pushup(int &o)
{
    t [o] .siz = t [t [o] .ch [0]]. siz + t [t [o] .ch [1]]. siz + t [o] .num;
}
void rotate(int &o,int d)
{
    int u=t[o].ch[d];
    t[o].ch[d]=t[u].ch[d^1];
    t[u].ch[d^1]=o;
    t [u] .you = t [o] .you;
    pushup(o);
    o=u;
}
void add(int &o,int x)
{
    if(!o)
    {
        o=newnode();
        t[o].val=x;
        return;
    }
    if(t[o].val==x)
    {
        t [o] .num ++; t [o] .you ++;
        return;
    }
    int d=t[o].val<x;
    add(t[o].ch[d],x);
    pushup(o);
    if(t[t[o].ch[d]].pri<t[o].pri)rotate(o,d);
}
void del(int &o,int x)
{
    if(!o)return;
    if(t[o].val==x)
    {
        if(t[o].num>1)t[o].num--;
        else if(t[o].ch[1]*t[o].ch[0]==0)//
            o=t[o].ch[1]+t[o].ch[0];
        else
        {
            int d=t[t[o].ch[0]].pri<t[t[o].ch[1]].pri;
            rotate(o,d^1);
            del (o, x); // o!
        }
        pushup(o);
        return;
    }
    int d=t[o].val<x;
    del (t [o] .ch [d], x);
    pushup(o);
}
int query(int &o,int x)
{
    if(!o)return 0;
    if(t[o].val==x)return t[t[o].ch[0]].siz+1;
    int d=t[o].val<x;
    if(!d)return query(t[o].ch[d],x);
    return query(t[o].ch[d],x)+t[o].num+t[t[o].ch[0]].siz;
}
int qr(int &o,int x)
{
    if(!o||!x)return 0;
    int d = xt [t [o] .ch [0]]. you;
    if(d<=0)return qr(t[o].ch[0],x);
    if(d<=t[o].num)return t[o].val;
    return qr(t[o].ch[1],x-t[t[o].ch[0]].siz-t[o].num);
}
int pre(int &o,int x)
{
    if(!o)return -inf;//
    if(t[o].val<x)return max(t[o].val,pre(t[o].ch[1],x));
    return pre(t[o].ch[0],x);
}
int lst(int &o,int x)
{
    if(!o)return inf;//
    if(t[o].val>x)return min(t[o].val,lst(t[o].ch[0],x));
    return lst(t[o].ch[1],x);
}
intmain()
{
    scanf("%d",&n);
    for(int i=1,x,opt;i<=n;i++)
    {
        scanf("%d%d",&opt,&x);
        if(opt==1)add(rt,x);//Insert x number
        if(opt==2)del(rt,x);//Delete x number (if there are multiple identical numbers, only delete one)
        if(opt==3)printf("%d\n",query(rt,x));
        //Query the ranking of the number of x (the ranking is defined as the number of numbers smaller than the current number + 1, if there are multiple identical numbers, output the smallest ranking)
        if(opt==4)printf("%d\n",qr(rt,x));//Query the number of rank x
        if(opt==5)printf("%d\n",pre(rt,x));//Seek the predecessor of x (the predecessor is defined as the largest number less than x)
        if(opt==6)printf("%d\n",lst(rt,x));//Seek the successor of x (the successor is defined as the smallest number greater than x)
    }
    return 0;
}