动态内存Treap

注意root的v要给一个很奇怪的数，null的s是0。

 #include <cstdio>
 #include <iostream>
 #include <algorithm>
 #include <cstring>
 #include <cmath>
 #include <ctime>
 #include <queue>
 using namespace std;
 const int maxn =  + ;
 struct Node{
     int v, r, s;
     Node* ch[];
     void maintain(){
         s = ch[] -> s + ch[] -> s + ;
         return ;
     }
 }*null = new Node(), *root, nodes[maxn];
 queue<Node*> RAM;
 int tot = , m;
 void init(Node* &o, int v){
     o -> ch[] = o -> ch[] = null;
     o -> s = ;
     o -> r = rand();
     o -> v = v;
     return ;
 }
 Node* node(){
     Node* o;
     if(!RAM.empty()) o = RAM.front(), RAM.pop();
     else o = &nodes[tot ++];
     return o;
 }
 void del(Node* &o){
     RAM.push(o);
     o = null;
     return ;
 }
 void rotate(Node* &o, int d){
     Node* k = o -> ch[d ^ ]; o -> ch[d ^ ] = k -> ch[d]; k -> ch[d] = o;
     o -> maintain(); k -> maintain(); o = k; return ;
 }
 void insert(Node* &o, int v){
     if(o == null){
         o = node();
         init(o, v);
     }
     else{
         int d = v > o -> v;
         insert(o -> ch[d], v);
         if(o -> ch[d] -> r > o -> r) rotate(o, d ^ ); //!
         else o -> maintain();
     }
     return ;
 }
 void remove(Node* &o, int v){
     if(o == null) return ;
     if(o -> v == v){
         if(o -> ch[] != null && o -> ch[] != null){
             int d = o -> ch[] -> r > o -> ch[] -> r;
             rotate(o, d); remove(o -> ch[d], v);
         }
         else{
             Node* k = o;
             if(o -> ch[] != null) o = o -> ch[];
             else o = o -> ch[];
             del(k);
         }
     }
     else remove(o -> ch[v > o -> v], v);
     if(o != null) o -> maintain();
     return ;
 }
 bool find(Node* &o, int v){
     if(o == null) return false;
     if(v == o -> v) return true;
     return find(o -> ch[v > o -> v], v);
 }
 void print(Node* &o){
     if(o == null) return ;
     print(o -> ch[]);
     printf("%d ", o -> v);
     print(o -> ch[]);
     return ;
 }
 void read(int &x){
     x = ; int sig = ; char ch = getchar();
     while(!isdigit(ch)) { if(ch == '-') sig = -; ch = getchar(); }
     while(isdigit(ch)) x =  * x + ch - '', ch = getchar();
     x *= sig; return ;
 }
 void init(){
     srand(time());
     null -> s = ;
     root = node();
     init(root, -);
     return ;
 }
 void work(){
 
     return ;
 }
 void print(){
 
     return ;
 }
 int main(){
     init();
     work();
     print();
     return ;
 }