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Treap 名次树(sbt) 动态插入,查询第k大

#include<iostream>#include<cstring>#include<set>#include<map>#include<cmath>#include<stack>#include<queue>#include<deque>#include<list>#include<algorithm>#include<stdio.h>#include<iomanip>#define rep(i,n) for(int i=0;i<n;++i)#define fab(i,a,b) for(int i=a;i<=b;++i)#define fba(i,b,a) for(int i=b;i>=a;--i)#define PB push_back#define INF 0x3f3f3f3f#define MP make_pair#define lson l,m,rt<<1#define rson m+1,r,rt<<1|1#define sf scanf#define pf printf#define LL long longconst int N=1005;using namespace std;typedef pair<int,int>PII;struct Node{    Node* ch[2];//left&right subtree    int r,v,s;//r priority; v value; s size of the subtree    Node(int v):v(v){ch[0]=ch[1]=NULL;r=rand();s=1;}    bool operator<(const Node& rhs)const{        return r<rhs.r;    }    int cmp(int x)const{       if(x==v)return -1;       return x<v?0:1;    }    void maintain(){        s=1;        if(ch[0]!=NULL)s+= ch[0]->s;        if(ch[1]!=NULL)s+= ch[1]->s;    }};bool find(Node* o,int x){    while(o!=NULL){        int d=o->cmp(x);        if(d==-1)return true;        o=o->ch[d];    }    return false;}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;}//箬不允许出现相同节点,那么调用之前先调用find判断是否可插入,remove类似void insert(Node* &o,int x){    if(o==NULL)o=new Node(x);    else{        int d= (x<o->v?0:1);//这里相同节点是放到右仔树,也因此不能用cmp        insert(o->ch[d],x);        if(o->ch[d]>o)rotate(o,d^1);    }    o->maintain();}void remove(Node* &o,int x){    int d=o->cmp(x);    if(d==-1){       Node* u=o;       if(o->ch[0]!=NULL && o->ch[1]!=NULL){           int d2= o->ch[0] > o->ch[1] ? 1 : 0;           rotate(o,d2);           remove(o->ch[d2],x);       }else{            if(o->ch[0]==NULL)o=o->ch[1];            else o=o->ch[0];            delete u;       }    }else{      remove(o->ch[d],x);    }    if(o!=NULL)o->maintain();}Node* root[maxn];int Kth(Node* o,int k){    if(o==NULL||k<=0||k>o->s)return 0;//不存在第k大    int s=(o->ch[1]==NULL?0:o->ch[1]->s);    if(k==s+1)return o->v;    else if(k<=s)return Kth(o->ch[1],k);    else return Kth(o->ch[0],k-s-1);}void mergeto(Node* &src,Node* &dest){//启发式合合并两颗子树,把小的合到大的里面,复杂度n(logn)^2    if(src->ch[0]!=NULL)mergeto(src->ch[0],dest);    if(src->ch[1]!=NULL)mergeto(src->ch[1],dest);    insert(dest,src->v);    delete src;    src=NULL;}void removetree(Node* &x){//删除整颗树,释放空间    if(x->ch[0]!=NULL)removetree(x->ch[0]);    if(x->ch[1]!=NULL)removetree(x->ch[1]);    delete x;    x=NULL;}

 

Treap 名次树(sbt) 动态插入,查询第k大