Treap模板

#include <iostream>
#include <algorithm>
#include <cstring>
#include <string>
#include <cstdio>
#include <vector>
using namespace std;

#define RG register int
#define LL long long

template<typename elemType>
inline void Read(elemType &T){
    elemType X=0,w=0; char ch=0;
    while(!isdigit(ch)) {w|=ch=='-';ch=getchar();}
    while(isdigit(ch)) X=(X<<3)+(X<<1)+(ch^48),ch=getchar();
    T=(w?-X:X);
}

template<typename elemType,size_t MAX_SIZE=100010>
struct Treap{
    struct TreapNode{
        elemType val;
        int rnd,size,num,son[2];
        int &operator[](int x){return son[x];}
    }T[MAX_SIZE];
    
    int root,cnt;
    Treap():root(0),cnt(0){}

    void push_up(int u){T[u].size=T[T[u][0]].size+T[T[u][1]].size+T[u].num;}

    int new_node(elemType val){//新建值为val的结点
        ++cnt;T[cnt].val=val;
        T[cnt].size=T[cnt].num=1;
        T[cnt].rnd=rand();
        return cnt;
    }

    void rotate(int &u,int d){//d=0左旋,d=1右旋
        int v=T[u][d^1];
        T[u][d^1]=T[v][d];
        T[v][d]=u;
        u=v;push_up(T[u][d]);push_up(u);
    }

    void insert_node(int &u,elemType val){
        if(!u){u=new_node(val);return;}
        if(T[u].val==val){++T[u].num;push_up(u);return;}
        int d=(val<T[u].val)?0:1;
        insert_node(T[u][d],val);
        if(T[u].rnd>T[T[u][d]].rnd) rotate(u,d^1);
        push_up(u);
    }

    void insert(elemType val){insert_node(root,val);}

    void delete_node(int &u,elemType val){
        if(!u) return;
        if(T[u].val==val){
            if(T[u].num>1){--T[u].num;push_up(u);return;}
            if(T[u][0] && !T[u][1]){rotate(u,1);delete_node(T[u][1],val);push_up(u);}
            else if(!T[u][0] && T[u][1]){rotate(u,0);delete_node(T[u][0],val);push_up(u);}
            else if(T[u][0] && T[u][1]){
                if(T[T[u][0]].rnd<T[T[u][1]].rnd){rotate(u,1);delete_node(T[u][1],val);}
                else{rotate(u,0);delete_node(T[u][0],val);}
                push_up(u);
            }else u=0;
            return;
        }
        if(val<T[u].val) delete_node(T[u][0],val);
        else delete_node(T[u][1],val);
        push_up(u);
    }
    void delete_node(elemType val){delete_node(root,val);}

    int get_rank(int u,elemType val){
        if(!u) return 1;
        if(T[u].val==val) return T[T[u][0]].size+1;
        else if(val<T[u].val) return get_rank(T[u][0],val);
        return T[T[u][0]].size+T[u].num+get_rank(T[u][1],val);
    }
    int get_rank(elemType val){return get_rank(root,val);}

    int get_kth(int u,int kth){//返回第k大的结点
        if(u==0||kth>T[u].size) return 0;
        if(T[T[u][0]].size<kth && kth<=T[T[u][0]].size+T[u].num) return u;
        else if(kth<=T[T[u][0]].size) return get_kth(T[u][0],kth);
        return get_kth(T[u][1],kth-T[T[u][0]].size-T[u].num);
    }
    elemType get_kth_val(int kth){return T[get_kth(root,kth)].val;}
    //返回第k大的结点的值

    int get_predecessor(elemType val){//返回val的(严格)前驱结点
        int u=root,v;
        while(u){
            if(T[u].val<val){v=u;u=T[u][1];}
            else u=T[u][0];
        }
        return v;
    }
    elemType get_predecessor_val(elemType val){return T[get_predecessor(val)].val;}
    //返回val的(严格)前驱结点的值

    int get_successor(elemType val){//返回val的(严格)后继结点
        int u=root,v;
        while(u){
            if(val<T[u].val){v=u;u=T[u][0];}
            else u=T[u][1];
        }
        return v;
    }
    elemType get_successor_val(elemType val){return T[get_successor(val)].val;}
    //返回val的(严格)后继结点的值

    void output_tree(int u){//中序遍历Treap
        if(!u) return;
        output_tree(T[u][0]);
        cout<<T[u].val<<endl;
        output_tree(T[u][1]);
    }
};
Treap<int> Tree;
int n;

int main(){
    Read(n);
    for(RG i=1;i<=n;++i){
        int opt,x;
        Read(opt);Read(x);
        if(opt==1) Tree.insert(x);
        else if(opt==2) Tree.delete_node(x);
        else if(opt==3) printf("%d
",Tree.get_rank(x));
        else if(opt==4) printf("%d
",Tree.get_kth_val(x));
        else if(opt==5) printf("%d
",Tree.get_predecessor_val(x));
        else if(opt==6) printf("%d
",Tree.get_successor_val(x));
        else if(opt==7) Tree.output_tree(Tree.root);
    }
    return 0;
}