模板_Splay Tree

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#include<cstdio>#include<climits>#include<cstdlib>#include<iostream>using namespace std;#define INF INT_MAX/3*2struct SplayTree{    struct Node{        Node *ch[2];        int r,v,s,size;        Node(int v,Node* nl):v(v){size=s=1;r=rand();ch[0]=ch[1]=nl;}        void maintain(){size=ch[0]->size+s+ch[1]->size;}    }*root,*null;    SplayTree(){        null=new Node(0,0);null->r=INT_MAX;null->size=null->s=0;        null->ch[0]=null->ch[1]=null;root=null;    }    void rotate(Node* &o,int d) {        Node* k=o->ch[d^1];o->ch[d^1]=k->ch[d],k->ch[d]=o;        o->maintain(),k->maintain();o=k;    }    void insert(Node* &o,int x){        if(o==null){o=new Node(x,null);return;}        if(o->v==x){o->s++,o->size++;return;}        insert(o->ch[x>o->v],x);        if(o->ch[x>o->v]->r<o->r) rotate(o,x<o->v);        else o->maintain();    }    void remove(Node* &o,int x){        if(o->v==x){            if(o->s>1){o->s--;o->size--;return;}            int d=o->ch[0]->r>o->ch[1]->r;            if(o->ch[d]==null){delete o;o=null;return;}            rotate(o,d);remove(o->ch[d^1],x);        }        else remove(o->ch[x>o->v],x);        o->maintain();    }    int kth(Node *o,int x){        int d=o->ch[0]->size;        if(x<=d) return kth(o->ch[0],x);        else if(x>d+o->s) return kth(o->ch[1],x-d-o->s);        return o->v;    }    int rank(Node *o,int x){        int d=o->ch[0]->size;        if(x<o->v) return rank(o->ch[0],x);        else if(x>o->v) return rank(o->ch[1],x)+d+o->s;        return d;    }    int prev(Node *o,int x){        if(o==null) return -INF;        if(x==o->v&&o->s>1) return o->v;        else if(x<=o->v) return prev(o->ch[0],x);        return max(o->v,prev(o->ch[1],x));    }    int next(Node* o,int x){        if(o==null) return INF;        if(x==o->v&&o->s>1) return o->v;        else if(x>=o->v) return next(o->ch[1],x);        return min(o->v,next(o->ch[0],x));    }    int cmprk(Node *o,int k){        int d;        if((o->ch[0]->size)<k&&(o->ch[0]->size+o->s)>=k) d=-1;        else if(o->ch[0]->size>=k) d=0;else d=1;        return d;    }/*  void splay(Node* &o,int x){//单旋        int d=o->ch[0]==null?0:o->ch[0]->size;        if(d<x){            if(d+o->s<x){splay(o->ch[1],x-d-o->s);rotate(o,0);}            else return;        }        else{splay(o->ch[0],x);rotate(o,1);}    }*/    void splay(Node* &o,int k) {//双旋        if(o==null) return;        int d=cmprk(o,k);        if(d==1) k-=o->ch[0]->size+o->s;        if(d!=-1&&o->ch[d]!=null){            Node *p=o->ch[d];            int d2=cmprk(o->ch[d],k);            if(d2!=-1&&p->ch[d2]!=null){                int k2=(d2==0?k:k-(p->ch[d2]->size+p->s));                splay(p->ch[d2],k2);                if(d==d2) rotate(o,d^1);else rotate(o->ch[d],d);            }            rotate(o,d^1);        }    }    Node *merge(Node *left,Node *right){//合并          splay(left,left->s);left->ch[1]=right;        left->maintain();return left;    }    void split(Node *o,int k,Node* &left,Node* &right){//分裂 前K小在left中其余在right中         splay(o,k);left=o;right=o->ch[1];        o->ch[1]=null;left->maintain();     }}T;