Treap（模板）

人生第一次平衡树，Treap板子

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<ctime>

using namespace std;

struct Treenode
{
    int size;
    int fix;
    int weight;
    int key;
    Treenode *left;
    Treenode *right;
};

class Treaptree
{
    private:
        Treenode *null;
    public:
        Treenode *root;
        Treaptree()
        {
            null=new Treenode;
            null->key=0;
            null->weight=0;
            null->size=0;
            null->left=null;
            null->right=null;
            null->fix=0;
            root=null;
        } 
    
    void Treap_left(Treenode *now)
    {
        Treenode *tmp=now->right;
        now->right=tmp->left;
        tmp->left=now;
        tmp->size=now->size;
        now->size=now->left->size+now->right->size+now->weight;
        now=tmp;
    }
    
    void Treap_right(Treenode *now)
    {
        Treenode *tmp=now->left;
        now->left=tmp->right;
        tmp->right=now;
        tmp->size=now->size;
        now->size=now->left->size+now->right->size+now->weight;
        now=tmp;
    }
    
    void insert(Treenode *&now,int key)
    {
        if(now==null)
        {
            now=new Treenode;
            now->key=key;
            now->size=1;
            now->weight=1;
            now->fix=rand();
            now->left=null;
            now->right=null;
        }
        else if(key==now->key)
        {
            now->weight++;
        }
        else if(key<now->key)
        {
            insert(now->left,key);
            if(now->left->fix<now->fix) Treap_right(now);    
        }
        else if(key>now->key)
        {
            insert(now->right,key);
            if(now->left->fix<now->fix) Treap_left(now);
        }
        now->size=now->left->size+now->right->size+now->weight;
    }
    
    bool find(Treenode *now,int key)
    {
        if(now==null)return false;
        if(key<now->key)return find(now->left,key);
        else if(key>now->key)return find(now->right,key);
        else return true;
    }
    
    void Delete(Treenode *&now,int key)
    {
        if(now==null)return;
        if(key<now->key)Delete(now->left,key);
        else if(key>now->key)Delete(now->right,key);
        else
        {
            if(now->weight>1)now->weight--;
            else
            {
                if(now->left==null&&now->right==null)
                {
                    delete now;
                    now=null;
                }
                else
                {
                    if(now->left->fix<now->right->fix)Treap_left(now);
                    else Treap_right(now);
                    Delete(now,key);
                }
                now->size=now->left->size+now->right->size+now->weight;
            }
        }
    }
};

int main()
{
    
    return 0;
}