贴一发SBT的模板............慢慢熟悉


 

#include <iostream>
#include <algorithm>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <string>
#include <vector>
#include <set>
#include <queue>
#include <stack>
#include <climits>//形如INT_MAX一类的
#define MAX 111111
#define INF 0x7FFFFFFF
#define REP(i,s,t) for(int i=(s);i<=(t);++i)
#define ll long long
#define mem(a,b) memset(a,b,sizeof(a))
#define mp(a,b) make_pair(a,b)
#define L(x) x<<1
#define R(x) x<<1|1
# define eps 1e-5
//#pragma comment(linker, "/STACK:36777216") ///传说中的外挂
using namespace std;

struct sbt {
    int l,r,s,key;
} tr[MAX];
int top , root;
void left_rot(int &x) {
    int y = tr[x].r;
    tr[x].r = tr[y].l;
    tr[y].l = x;
    tr[y].s = tr[x].s; //转上去的节点数量为先前此处节点的size
    tr[x].s = tr[tr[x].l].s + tr[tr[x].r].s + 1;
    x = y;
}

void right_rot(int &x) {
    int y = tr[x].l;
    tr[x].l = tr[y].r;
    tr[y].r = x;
    tr[y].s = tr[x].s;
    tr[x].s = tr[tr[x].l].s + tr[tr[x].r].s + 1;
    x = y;
}

void maintain(int &x,bool flag) {
    if(flag == 0) { //左边
        if(tr[tr[tr[x].l].l].s > tr[tr[x].r].s) {//左孩子左子树size大于右孩子size
            right_rot(x);
        } else if(tr[tr[tr[x].l].r].s > tr[tr[x].r].s) {//左孩子右子树size大于右孩子size
            left_rot(tr[x].l);
            right_rot(x);
        } else return ;
    } else { //右边
        if(tr[tr[tr[x].r].r].s > tr[tr[x].l].s) { //右孩子的右子树大于左孩子
            left_rot(x);
        } else if(tr[tr[tr[x].r].l].s > tr[tr[x].l].s) { //右孩子的左子树大于左孩子
            right_rot(tr[x].r);
            left_rot(x);
        } else return ;
    }
    maintain(tr[x].l,0);
    maintain(tr[x].r,1);
}

void insert(int &x,int key) {
    if(x == 0) { //空节点
        x = ++ top;
        tr[x].l = tr[x].r = 0;
        tr[x].s = 1;
        tr[x].key = key;
    } else {
        tr[x].s ++;
        if(key < tr[x].key) insert(tr[x].l,key);
        else insert(tr[x].r,key);
        maintain(x,key >= tr[x].key);
    }
}
int del(int &p,int w) {
    if (tr[p].key==w || (tr[p].l == 0 && w < tr[p].key) || (tr[p].r == 0 && w > tr[p].key)) {
        int delnum = tr[p].key;
        if (tr[p].l == 0 || tr[p].r == 0) p = tr[p].l + tr[p].r;
        else tr[p].key=del(tr[p].l,INF);
        return delnum;
    }
    if (w < tr[p].key) return del(tr[p].l,w);
    else return del(tr[p].r,w);
}

int remove(int &x,int key) {
    int k;
    tr[x].s --;
    if(key == tr[x].key || (key < tr[x].key && tr[x].l == 0) || (key > tr[x].key && tr[x].r == 0)) {
        k = tr[x].key;
        if(tr[x].l && tr[x].r) {
            tr[x].key = remove(tr[x].l,tr[x].key + 1);
        } else {
            x = tr[x].l + tr[x].r;
        }
    } else if(key > tr[x].key) {
        k = remove(tr[x].r,key);
    } else if(key < tr[x].key) {
        k = remove(tr[x].l,key);
    }
    return k;
}
int getmin() { //二叉搜索树找最小值
    int x;
    for(x = root; tr[x].l; x = tr[x].l) ;
    return tr[x].key;
}
int getmax() {
    int x;
    for(x = root ; tr[x].r; x = tr[x].r) ;
    return tr[x].key;

}
int pred(int &x,int y,int key)
//前驱 小于
{
    if(x == 0) return y;
    if(tr[x].key < key)//加上等号，就是小于等于
        return pred(tr[x].r,x,key);
    else return pred(tr[x].l,y,key);
}//pred(root,0,key)
int succ(int &x,int y,int key) { //后继 大于
    if(x == 0) return y;
    if(tr[x].key > key)
        return succ(tr[x].l,x,key);
    else return succ(tr[x].r,y,key);
}
int select(int &x,int k) { //求第k小数
    int r = tr[tr[x].l].s + 1;
    if(r == k) return tr[x].key;
    else if(r < k) return select(tr[x].r,k - r);
    else return select(tr[x].l,k);
}
int rank(int &x,int key) { //求第K小数的逆运算
    if(key < tr[x].key) return rank(tr[x].l,key);
    else if(key > tr[x].key) return rank(tr[x].r,key);
    else return tr[tr[x].l].s + 1;
}

void inorder(int &x) {
    if(x == 0) return;
    else {
        inorder(tr[x].l);
        cout<< x <<" "<< tr[x].key << " " <<tr[x].s << " " <<tr[tr[x].l].key << " " << tr[tr[x].r].key << endl;
        inorder(tr[x].r);
    }
}